Re: AIX 5.1/5.2/5.3 local root exploits (paginit issue)

[Shiva Persaud <shivapd () us ibm com>]

cees-bart <ceesb () cs ru nl> wrote on 12/20/2004 05:10:41 AM:

> 2) the second is a classical stack overflow in a tool called paginit.

Note from the advisory below that AIX 5.1 is not affected by this issue.

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

IBM SECURITY ADVISORY

First Issued: Mon Dec 20 12:57:11 CST 2004

===========================================================================
                           VULNERABILITY SUMMARY

VULNERABILITY:      Buffer overflow vulnerability in paginit command
                    allows local users to gain root privileges.

PLATFORMS:          AIX 5.2 and 5.3.

SOLUTION:           Apply the workaround or APARs as described below.

THREAT:             A local user can gain root privileges.

CERT VU Number:     N/A
CVE Number:         N/A
===========================================================================
                           DETAILED INFORMATION


I.  Description
===============

A vulnerability was discovered in the paginit command that allows a local
user to gain root privileges. Exploits for this vulnerability are publicly
available.

The command affected by this issue ships as part of the bos.rte.security
fileset. This fileset is installed as part of the Base Operating System
Installation.


II. Impact
==========
Any local user can exploit this buffer overflow vulnerability to gain root
privileges.


III.  Solutions
===============

A. Official Fix

IBM provides the following fixes:

      APAR number for AIX 5.2.0: IY64522 (available)
      APAR number for AIX 5.3.0: IY64312 (available)


NOTE: Affected customers are urged to upgrade to 5.2.0 or 5.3.0 at the
latest maintenance level. Although a related AIX 5.1 APAR is available,
this issue is not exploitable on AIX 5.1 since the paginit command
is not available on 5.1.

B. Workaround

Setting the file mode bits to 500 will allow only the root user to execute
the paginit command. This can be done by executing the following command 
as
root:

# chmod 500 /usr/bin/paginit

Verify that the file mode bits have been changed to 500:

# ls -la /usr/bin/paginit
- -r-x------  1 root security 7354 2002-09-15 20:39 /usr/bin/paginit


IV. Obtaining Fixes
===================

AIX Version 5 APARs can be downloaded from the eServer pSeries Fix Central
web site:

     http://www-912.ibm.com/eserver/support/fixes/fcgui.jsp

Security related Emergency Fixes can be downloaded from:

     ftp://aix.software.ibm.com/aix/efixes/security


V.  Contact Information
=======================

If you would like to receive AIX Security Advisories via email, please 
visit:
     https://techsupport.services.ibm.com/server/pseries.subscriptionSvcs

Comments regarding the content of this announcement can be directed to:

     security-alert () austin ibm com

To request the PGP public key that can be used to communicate securely
with the AIX Security Team send email to security-alert () austin ibm com
with a subject of "get key". The key can also be downloaded from a
PGP Public Key Server. The key id is 0x9391C1F2.

Please contact your local IBM AIX support center for any assistance.

eServer is a trademark of International Business Machines Corporation.
IBM, AIX and pSeries are registered trademarks of International Business
Machines Corporation. All other trademarks are property of their
respective holders.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (MingW32)

iD8DBQFBx3g8xwSSvpORwfIRAlAhAJ9b9z6NyUOMWt5hjWQyRWFTuxlVowCfSDGv
JnduPgdIMwORnJAKHP9Nenw=
=6/oH
-----END PGP SIGNATURE-----