-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 IBM SECURITY ADVISORY First Issued: The most recent version of this document is available here: http://aix.software.ibm.com/aix/efixes/security/muxatmd_advisory.asc or ftp://aix.software.ibm.com/aix/efixes/security/muxatmd_advisory.asc VULNERABILITY SUMMARY VULNERABILITY: AIX muxatmd buffer overflow PLATFORMS: AIX 5.2, 5.3, 6.1 SOLUTION: Apply the fix or workaround as described below. THREAT: A local attacker may execute arbitrary code as root. CERT VU Number: n/a CVE Number: n/a Reboot required? NO Workarounds? YES Protected by FPM? YES (high, medium, or low) Protected by SED? YES DETAILED INFORMATION I. DESCRIPTION The muxatmd command contains a buffer which can overflow. A local attacker may exploit this overflow to execute arbitrary code with root privileges because the command is setuid root. The following file is vulnerable: /usr/sbin/muxatmd II. PLATFORM VULNERABILITY ASSESSMENT To determine if your system is vulnerable, execute the following command: lslpp -L devices.common.IBM.atm.rte The following fileset levels are currently vulnerable: AIX Fileset Lower Level Upper Level ---------------------------------------------------------- devices.common.IBM.atm.rte 5.2.0.51 5.2.0.97 devices.common.IBM.atm.rte 5.3.0.60 5.3.0.63 devices.common.IBM.atm.rte 5.3.7.0 5.3.7.2 devices.common.IBM.atm.rte 5.3.8.0 5.3.8.0 devices.common.IBM.atm.rte 5.3.9.0 5.3.9.0 devices.common.IBM.atm.rte 6.1.0.0 6.1.0.1 devices.common.IBM.atm.rte 6.1.1.0 6.1.1.0 devices.common.IBM.atm.rte 6.1.2.0 6.1.2.0 III. SOLUTIONS A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR number Availability ---------------------------------------------------- 5.2.0 IZ48495 07/22/2009 5.3.0 IZ48496 07/01/2009 5.3.7 IZ48499 07/01/2009 5.3.8 IZ48500 07/01/2009 5.3.9 IZ48501 07/01/2009 6.1.0 IZ48502 06/03/2009 6.1.1 IZ48561 06/03/2009 6.1.2 IZ48562 06/03/2009 Subscribe to the APARs here: http://www.ibm.com/support/docview.wss?uid=isg1IZ48495 http://www.ibm.com/support/docview.wss?uid=isg1IZ48496 http://www.ibm.com/support/docview.wss?uid=isg1IZ48499 http://www.ibm.com/support/docview.wss?uid=isg1IZ48500 http://www.ibm.com/support/docview.wss?uid=isg1IZ48501 http://www.ibm.com/support/docview.wss?uid=isg1IZ48502 http://www.ibm.com/support/docview.wss?uid=isg1IZ48561 http://www.ibm.com/support/docview.wss?uid=isg1IZ48562 By subscribing, you will receive periodic email alerting you to the status of the APAR, and a link to download the fix once it becomes available. B. FIXES Fixes are now available. The fixes can be downloaded from: http://aix.software.ibm.com/aix/efixes/security/muxatmd_fix.tar ftp://aix.software.ibm.com/aix/efixes/security/muxatmd_fix.tar The links above are to a tar file containing this signed advisory, fix packages, and PGP signatures for each package. AIX Level Fix ---------------------------------------------------- 5.2.0 TL10 IZ48495_10.090408.epkg.Z 5.3.0 TL6 IZ48496_06.090408.epkg.Z 5.3.7 IZ48499_07.090408.epkg.Z 5.3.8 IZ48500_08.090408.epkg.Z 5.3.9 IZ48501_09.090408.epkg.Z 6.1.0 IZ48502_00.090408.epkg.Z 6.1.1 IZ48561_01.090408.epkg.Z 6.1.2 IZ48562_02.090408.epkg.Z To extract the fixes from the tar file: tar xvf muxatmd_fix.tar cd muxatmd_fix 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 ------------------------------------------------------------------ 180f448dcbddeaaea2070daa50978f0bd0b2fdd2 IZ48495_10.090408.epkg.Z ee85a18106d7e0b09b06576f08cfb545fb06b9f7 IZ48496_06.090408.epkg.Z 0a5c7ec45e98c6e0beac89de13852fbab4992b7b IZ48499_07.090408.epkg.Z 78665878354668ed415a4dbad018fbf06d5140cb IZ48500_08.090408.epkg.Z de7e8056650767d480dbc099e372332b39748b86 IZ48501_09.090408.epkg.Z 2f3e0cd961a85822bace41f5c2a538e2df74a59e IZ48502_00.090408.epkg.Z 861973dd1ddeadd0969db52cf9342984ed0e96c2 IZ48561_01.090408.epkg.Z adacb27d2811cac2e47d06ef4724b5b8707aa714 IZ48562_02.090408.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 C. INTERIM 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. Interim fixes have had limited functional and regression testing but not the full regression testing that takes place for Service Packs; thus, IBM does not warrant the fully correct functionality of an interim fix. Interim fix management documentation can be found at: http://www14.software.ibm.com/webapp/set2/sas/f/aix.efixmgmt/home.html To preview an interim fix installation: emgr -e ipkg_name -p # where ipkg_name is the name of the # interim fix package being previewed. To install an interim fix package: emgr -e ipkg_name -X # where ipkg_name is the name of the # interim fix package being installed. IV. WORKAROUNDS There are two workarounds available. A. OPTION 1 Change the permissions of these commands to remove the setuid bit using the following commands: chmod 500 /usr/sbin/muxatmd NOTE: chmod will disable functionality of these commands for all users except root. B. OPTION 2 Use the File Permissions Manager (fpm) command to manage setuid and setgid programs. fpm documentation can be found in the AIX 6 Security Redbook at: http://www.redbooks.ibm.com/abstracts/sg247430.html An fpm level of high, medium, or low will remove the setuid bit from the affected commands. For example: fpm -l high -p # to preview changes fpm -l high # to execute changes NOTE: Please review the documentation before execution. fpm will disable functionality of multiple commands for all users except root. V. OBTAINING FIXES AIX security fixes can be downloaded from: http://aix.software.ibm.com/aix/efixes/security or ftp://aix.software.ibm.com/aix/efixes/security AIX fixes can be downloaded from: http://www.ibm.com/eserver/support/fixes/fixcentral/main/pseries/aix NOTE: Affected customers are urged to upgrade to the latest applicable Technology Level and Service Pack. 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. Download the key from our web page: http://www.ibm.com/systems/resources/systems_p_os_aix_security_pgpkey.txt B. Download the key from a PGP Public Key Server. The key ID is: 0xADA6EB4D 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 This vulnerability was reported by iDefense Labs. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (AIX) iD8DBQFJ5fqHP9Qud62m600RArWJAKCQw/a9fd7EDxZXeyV/t+uVdQfnsgCfY/vN PMJwYfZ/ow9yGbXddMnVCtU= =vj5R -----END PGP SIGNATURE-----