-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 IBM SECURITY ADVISORY First Issued: Mon Sep 13 13:15:05 CDT 2010 | Updated: Tue Sep 14 11:22:12 CDT 2010 | Fixed APAR section | Updated: Wed Dec 1 13:56:04 CST 2010 | Updated workaround The most recent version of this document is available here: http://aix.software.ibm.com/aix/efixes/security/sa_snap_advisory.asc VULNERABILITY SUMMARY VULNERABILITY: AIX security vulnerabilities in sa_snap PLATFORMS: AIX 5.3, 6.1, and earlier releases VIOS 1.5, 2.1, and earlier releases SOLUTION: Apply the fix or workaround as described below. THREAT: A system group user may execute arbitrary code as root and delete sensitive files on the system. CERT VU Number: N/A CVE Number: N/A Reboot required? NO Workarounds? YES Protected by FPM? NO Protected by SED? NO Protected by AIXPERT? NO DETAILED INFORMATION I. DESCRIPTION a) A buffer overflow is created in program /usr/esa/sbin/sa_snap, resulting in potential privilege escalation by a system group users. b) In AIX 5.3, a system group user can delete sensitive files on the system. II. PLATFORM VULNERABILITY ASSESSMENT Note: To use the following commands on VIOS you must first execute: oem_setup_env To determine if your system is vulnerable, execute the following command: lslpp -L bos.esagent The following fileset levels are vulnerable: AIX Fileset Lower Level Upper Level ------------------------------------------------ bos.esagent 06.05.0010.0000 06.05.0010.0003 bos.esagent 06.05.0011.0000 06.05.0011.0004 bos.esagent 06.05.0012.0000 06.05.0012.0001 bos.esagent 06.06.0002.0000 06.06.0002.0005 bos.esagent 06.06.0003.0000 06.06.0003.0005 bos.esagent 06.06.0004.0000 06.06.0004.0007 bos.esagent 06.06.0005.0000 06.06.0005.0002 III. SOLUTION A. FIXES Fixes are now available. The fixes can be downloaded from: http://aix.software.ibm.com/aix/efixes/security/sa_snap_fix.tar The links above are to a tar file containing this signed advisory, fix packages, and PGP signatures for each package. AIX Level VIOS Level Fix ------------------------------------------------------------------- 5.3.10 1.5.2 IZ82630_10.100910.epkg.Z 5.3.11 IZ82245_11.100910.epkg.Z 5.3.12 IZ81819_12.100910.epkg.Z 6.1.2 2.1.0 IZ84167_02.100910.epkg.Z 6.1.3 2.1.1 IZ83909_03.100910.epkg.Z 6.1.4 2.1.2 IZ83975_04.100910.epkg.Z 6.1.5 2.1.3 IZ83942_05.100910.epkg.Z To extract the fixes from the tar file: tar xvf sa_snap_fix.tar cd sa_snap Verify you have retrieved the fixes intact: The checksums below were generated using the "csum -h SHA1" (sha1sum) commands and are as follows: csum -h SHA1 (sha1sum) filename ------------------------------------------------------------------ 1c86260dcaf2cdcd08f6646c98fcec9c0abeb1b6 IZ81819_12.100910.epkg.Z 3d0a20490c6271fb35afbe99cc028476b6ae8b68 IZ82245_11.100910.epkg.Z 6e67ebdfe904235099e2019b6118ee91ab162638 IZ82630_10.100910.epkg.Z 4d1b2f681103e7a0dcb88f20af17b0cc50d62b0d IZ83909_03.100910.epkg.Z 630ed06b834bc97a48411b2475f663125cb7b1ca IZ83942_05.100910.epkg.Z 954fc0b96abd0c2f293fb7a9a02487abf2d929b6 IZ83975_04.100910.epkg.Z e71a6e1e22119a41147fa5a68291db0f82a59c0f IZ84167_02.100910.epkg.Z To verify the sums, use the text of this advisory as input to csum or sha1sum. For example: csum -h SHA1 -i Advisory.asc sha1sum -c Advisory.asc These sums should match exactly. The PGP signatures in the tar file and on this advisory can also be used to verify the integrity of the fixes. If the sums or signatures cannot be confirmed, contact IBM AIX Security and describe the discrepancy at the following address: security-alert@austin.ibm.com B. FIX INSTALLATION IMPORTANT: If possible, it is recommended that a mksysb backup of the system be created. Verify it is both bootable and readable before proceeding. Fix management documentation can be found at: http://www14.software.ibm.com/webapp/set2/sas/f/aix.efixmgmt/home.html To preview fix installation: emgr -e fix_name -p # where fix_name is the name of the # fix being previewed. To install fix package: emgr -e fix_name -X # where fix_name is the name of the # fix being installed. C. APARS IBM has assigned the following APARs to this problem: AIX Level APAR number Service pack date -------------------------------------------------------- | 5.3.10 IZ82630 9/22/10 sp5 | 5.3.11 IZ82245 9/22/10 sp5 | 5.3.12 IZ81819 9/22/10 sp2 | 6.1.2 IZ84167 10/20/10 sp10 | 6.1.3 IZ83909 10/20/10 sp7 | 6.1.4 IZ83975 10/20/10 sp7 | 6.1.5 IZ83942 10/20/10 sp3 Subscribe to the APARs here: http://www.ibm.com/support/docview.wss?uid=isg1IZ82630 http://www.ibm.com/support/docview.wss?uid=isg1IZ82245 http://www.ibm.com/support/docview.wss?uid=isg1IZ81819 http://www.ibm.com/support/docview.wss?uid=isg1IZ84167 http://www.ibm.com/support/docview.wss?uid=isg1IZ83909 http://www.ibm.com/support/docview.wss?uid=isg1IZ83975 http://www.ibm.com/support/docview.wss?uid=isg1IZ83942 By subscribing, you will receive periodic email alerting you to the status of the APAR, and a link to download the service pack when it becomes available. IV. WORKAROUND The attacking user must be in the system group to exploit this vulnerability and the system group is considered a privileged group that only root can create. Please take this into consideration to prevent wrongly assigning group ids. | Remove group and other execute permission from sa_snap. VI. CONTACT INFORMATION If you would like to receive AIX Security Advisories via email, please visit: http://www.ibm.com/systems/support and click on the "My notifications" link. To view previously issued advisories, please visit: http://www14.software.ibm.com/webapp/set2/subscriptions/pqvcmjd Comments regarding the content of this announcement can be directed to: security-alert@austin.ibm.com To obtain the PGP public key that can be used to communicate securely with the AIX Security Team you can either: A. Send an email with "get key" in the subject line to: security-alert@austin.ibm.com B. Download the key from our web page: http://www.ibm.com/systems/resources/systems_p_os_aix_security_pgpkey.txt C. Download the key from a PGP Public Key Server. The key ID is: 0x28BFAA12 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. VII. ACKNOWLEDGMENTS Lucas McLane, CISSP for disclosing and providing PoC. Also, Joe Cushing for helping Lucas with AIX microcode upgrades. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (AIX) iD8DBQFM9qlg4fmd+Ci/qhIRArqTAJ9l30MbELVILuVesXzyAnnkit5JLgCfUIi4 HOo2kh95mWtene/CmdTxTrY= =pcmu -----END PGP SIGNATURE-----