COMMAND
axent
SYSTEMS AFFECTED
Axent 5.0 for Unix
PROBLEM
This information was forwarded to Security Focus. Certain checks
within Axent's ESM 5.0 for Unix may prevent legitimate users from
logging on to scanned hosts. Specifically, four checks within
the security auditing program may cause this denial of service:
* Check PATH using 'su'
* Check PATH by modifying startup script
* Check umask using 'su'
* Check umask by modifying startup script
These checks are not enabled in the default policy templates.
When ESM is checking PATH (or umask) values, it will 'su' to the
user's account. If the user's script calls a menu function, ESM
will not respond and the check will hang. To overcome this
problem, ESM copies the startup script to the /tmp directory,
adds additional values to the end of the script, and copies the
script back to the user's directory. The new values in the script
will echo the PATH and umask values to a file called .esmvalues in
the user's home directory the next time the user logs in. When
ESM is run again, it will read the contents of .esmvalues to
determine the PATH and umask values. This procedure eliminates
the problems associated with 'su'ing to the account and hanging
on a menu call.
Unfortunately, when ESM copies the file to /tmp, file ownership
and permissions are changed to 'root'. When the file is copied
back to the user's directory, only root has access - legitimate
users will not be able to execute their login script.
SOLUTION
This bug should be fixed in the upcoming 5.0.1 release. The first
statement indicates that users cannot log into scanned hosts.
This is not true--users can log in, but they will not be able to
access their startup scripts. This bug constitutes more of an
inconvenience to the user, than a security threat. The bug was
discovered a short time ago and there is a current procedure for
correcting the ownership of files that may have been affected.
Currently there is a newer version of the affected usrfiles
module that does not change the ownership of the startup scripts.
This procedure and/or the updated module can be obtained by
contacting AXENT support. This version of the usrfiles module is
also included in the August HotFix for ESM that customers can
remotely install on all systems. The hot fix is only needed for
ESM 5.0 UNIX agents. Earlier versions of ESM agents do not have
this problem. The fix will also be included in the upcoming ESM
5.0.1 release. As was indicated above, this check was not turned
on by default and most ESM 5.0 customers have probably not used
it. If you desire the procedure to correct the affected files or
the updated module, please contact AXENT support.