===================================================================== CERT-Renater Note d'Information No. 2007/VULN349 _____________________________________________________________________ DATE : 13/08/2007 HARDWARE PLATFORM(S) : / OPERATING SYSTEM(S) : AIX 5.2, AIX 5.3 running fileplace Command. ====================================================================== IBM SECURITY ADVISORY First Issued: Tue Aug 7 17:36:53 CDT 2007 =============================================================================== VULNERABILITY SUMMARY VULNERABILITY: AIX fileplace Command Buffer Overflow Vulnerability PLATFORMS: AIX 5.2, 5.3 SOLUTION: Apply the APAR, interim fix or workaround as described below. THREAT: An attacker may run arbitrary code with root privileges. CERT VU Number: n/a CVE Number: n/a =============================================================================== DETAILED INFORMATION I. OVERVIEW The fileplace command displays the placement of a specified file within the logical or physical volumes containing the file. II. DESCRIPTION A buffer overflow vulnerability exists in the fileplace command whereby a local user may execute arbitrary code with root privileges. III. IMPACT The successful exploitation of this vulnerability allows a non-privileged user to execute code with root privileges. IV. PLATFORM VULNERABILITY ASSESSMENT To determine if your system is vulnerable, run the following command: # lslpp -l | grep bos.perf.tools The following filesets levels are vulnerable: AIX Level Lower Level Upper Level ------------------------------------------------- 5.2.0 5.2.0.0 5.2.0.105 5.3.0 5.3.0.0 5.3.0.61 NOTE: IBM only supports the latest two releases (AIX 5.2 & 5.3) and the latest three Technology Levels (AIX 5.2 TL08, TL09, TL10 & AIX 5.3 TL04, TL05, TL06). Affected customers are urged to upgrade to the latest applicable Technology Level and Service Pack. V. SOLUTIONS A. APARS IBM provides the following fixes: AIX Level APAR number Availability -------------------------------------------------------------------- 5.2.0 IZ00154 Available 5.3.0 IZ00149 Available AIX Version 5 APARs can be downloaded from: http://www.ibm.com/servers/eserver/support/unixservers/aixfixes.html NOTE: Affected customers are urged to upgrade to the latest applicable Technology Level and Service Pack. B. INTERIM FIXES Interim fixes are available. The interim fix can be downloaded via ftp from: ftp://aix.software.ibm.com/aix/efixes/security/fileplace_ifix.tar.Z This is a compressed tarball containing this advisory, interim fix packages and PGP signatures for each package. The interim fixes below include prerequisite checking. This will enforce the correct mapping between the fixes and AIX Technology Levels. AIX Release & Technology Level Interim fix --------------------------------------------------------------- 5300-04 IZ00149_04.070614.epkg.Z 5300-05 IZ00149_05.070614.epkg.Z 5300-06 IZ00149_06.070614.epkg.Z 5200-08 IZ00154_08.070614.epkg.Z 5200-09 IZ00154_09.070614.epkg.Z 5200-10 IZ00154_10.070614.epkg.Z IMPORTANT: If possible, it is recommended that a mksysb backup of the system be created. Verify it is both bootable and readable before proceeding. These interim fixes have not been fully regression tested; thus, IBM does not warrant the fully correct functionality of the interim fix. Customers install the interim fix and operate the modified version of AIX at their own risk. Verify you have retrieved the fixes intact: The interim fixes below are named by using the technology level corresponding to the release that the fix applies to. The checksums below were generated using the "sum" and "md5sum" commands and are as follows: Filename sum md5sum ---------------------------------------------------------------------- IZ00149_04.070614.epkg.Z 07905 17 7fb600f44737f788f0a79fb6c4235172 IZ00149_05.070614.epkg.Z 40169 17 d8039bd0a0a253b0d52feaaa94c480a0 IZ00149_06.070614.epkg.Z 17005 17 d09b183dc32689b7b7b53e26bac24233 IZ00154_08.070614.epkg.Z 37336 17 e6568799884262a5c7620fd9171ae546 IZ00154_09.070614.epkg.Z 19912 17 b816616774d66acb565403282823e3d7 IZ00154_10.070614.epkg.Z 10830 17 98f71db66ed488d2528de7907c45b08f These sums should match exactly. The PGP signatures in the compressed tarball and on this advisory can also be used to verify the integrity of the various files they correspond to. If the sums or signatures cannot be confirmed, double check the command results and the download site address. If those are OK, contact IBM AIX Security at security-alert@austin.ibm.com and describe the discrepancy. C. INTERIM FIX INSTALLATION These packages use the new Interim Fix Management Solution to install and manage interim fixes. More information can be found at: http://www14.software.ibm.com/webapp/set2/sas/f/aix.efixmgmt/home.html To preview an epkg interim fix installation execute the following command: # emgr -e ipkg_name -p # where ipkg_name is the name of the # interim fix package being previewed. To install an epkg interim fix package, execute the following command: # emgr -e ipkg_name -X # where ipkg_name is the name of the # interim fix package being installed. The "X" flag will expand any filesystems if required. VI. WORKAROUNDS There are several workarounds, which may be implemented. A. OPTION 1 If the program is unnecessary, it may be removed with the following command: # rm -f /usr/bin/fileplace NOTE:To restore this command, the entire bos.perf.tools package must be reinstalled. B. OPTION 2 Change the permissions of this command to remove the setuid bit using the following command: # chmod 500 /usr/bin/fileplace NOTE: This will disable functionality of the command for all users except root. C. OPTION 3 Customers running AIX 5.3.0 TL06 may install the bos.rte.security fileset and take advantage of the 'fpm' command to disable the setuid capabilities of many SUID commands. The fileplace command is addressed by the medium and high fpm databases. D. OPTION 3 Stack execution disable may be enabled on machines running AIX 5.3 TL05 or later. VII. OBTAINING FIXES AIX Version 5 APARs can be downloaded from: http://www.ibm.com/servers/eserver/support/unixservers/aixfixes.html Security related Interim Fixes can be downloaded from: ftp://aix.software.ibm.com/aix/efixes/security VII. CONTACT INFORMATION If you would like to receive AIX Security Advisories via email, 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 request 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 a PGP Public Key Server. The key ID is: 0x4265D862 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. VIII. ACKNOWLEDGMENTS This vulnerability was discovered internal to IBM as part of its commitment to securing the AIX operating system. ====================================================================== ========================================================= Les serveurs de référence du CERT-Renater http://www.urec.fr/securite http://www.cru.fr/securite http://www.renater.fr ========================================================= + CERT-RENATER | tel : 01-53-94-20-44 + + 151 bd de l'Hopital | fax : 01-53-94-20-41 + + 75013 Paris | email: certsvp@renater.fr + =========================================================