Advisory ID: 11242000-02

Risk: Low

Title: catman temp file vulnerability.

Class: Design Error

Remotely Exploitable: no

Locally Exploitable: Yes

Vulnerability Description:

Through the use of symlinking temporary files created by /usr/bin/catman upon execution by root a local user can clobber root owned files.

Vulnerable Packages/Systems: Solaris 2.x Sparc/x86

Solution/Vendor Information/Workaround:

The vendor is currently working on a solution. See references section for Vendor contact information.

Sun BugID: 4392144

Fixed with SUN Patch:107038

Vendor notified on: 11/23/2000

Credits:

I alerted sun to this issue 11/23/2000 they responded 11/24/2000. Kudos to the Sun Engineering group. This response time should be a model to other vendors.

Technical Description:

The catman command creates preformatted versions of the online manual. It also creates the windex database for utilities like apropos and whatis. The problem lies with catman creating a temporary file in /tmp, the file has the form of /tmp/sman_pidofcatman. An attacker can monitor the process list for the execution of catman and create a symlink to a root owned file. catman will upon execution overwrite the contents of that file. This is a new bug for catman and is not addressed in the current patch cluster for Solaris 2.7 Sparc.

Exploit/Concept Code: see attachments.

References:

Sun Microsystems. http://www.sun.com 

Catman patch readme

Vapid Labs. http://vapid.dhs.org

Email: Larry W. Cashdollar <lwc@vapid.dhs.org> DISCLAIMER:

The contents of this advisory are copyright (c) 2000 Larry W. Cashdollar and may be distributed freely provided that no fee is charged for this distribution and proper credit is given.

Ver 2.4 11/29/2000