===================================================================== CERT-Renater Note d'Information No. 2007/VULN350 _____________________________________________________________________ DATE : 13/08/2007 HARDWARE PLATFORM(S) : / OPERATING SYSTEM(S) : AIX 5.2, AIX 5.3. ====================================================================== IBM SECURITY ADVISORY First Issued: Tue Aug 7 13:54:01 CDT 2007 =============================================================================== VULNERABILITY SUMMARY VULNERABILITY: AIX multiple buffer overflow vulnerabilities in configuration commands. PLATFORMS: AIX 5.2 & 5.3 SOLUTION: Apply the APAR, interim fix or workaround as described below. THREAT: An attacker may run arbitrary code as root privileges. CERT VU Number: n/a CVE Number: n/a =============================================================================== DETAILED INFORMATION I. OVERVIEW A. chpath The chpath command either changes the operational status of paths to the specified device (the -l Name flag) or it changes one, or more, attributes associated with a specific path to the specified device. B. rmpath The rmpath command deconfigures, and possibly undefines, one or more paths associated with the specified target device (-l Name). C. devinstall The devinstall command installs software support for devices. II. DESCRIPTION The above commands are vulnerable to buffer overflow conditions and may allow a user in the system group to execute arbitrary code with root privileges. III. IMPACT A user in the system group may execute arbitrary code with root privileges. IV. PLATFORM VULNERABILITY ASSESSMENT To determine if your system is vulnerable, run the following command: # lslpp -l | grep bos.rte.methods The following filesets are vulnerable: AIX Level Lower Level Upper Level ------------------------------------------------- 5.2.0 5.2.0.85 5.2.0.105 5.3.0 5.3.0.40 5.3.0.61 NOTE: The above filesets are those currently supported by IBM. Previous versions of the fileset may also be vulnerable. 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 IZ00531 Available 5.3.0 IZ01433 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/cmdcfg_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 --------------------------------------------------------------- 5200-08 IZ00529_08.070807.epkg.Z 5200-09 IZ00529_09.070807.epkg.Z 5200-10 IZ00529_10.070807.epkg.Z 5300-04 IZ01433_04.070807.epkg.Z 5300-05 IZ01433_05.070807.epkg.Z 5300-06 IZ01433_06.070807.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 ---------------------------------------------------------------------- IZ00529_08.070807.epkg.Z 52115 34 e11e4c5cc37ec26fde45d80703e76e19 IZ00529_09.070807.epkg.Z 35417 34 dd084a12d8a036b1071345ac4546c1c7 IZ00529_10.070807.epkg.Z 30938 34 1faf9dacf204895b8489c6eeaf82ae8d IZ01433_04.070807.epkg.Z 56171 37 07b177ca504041214ab35f8e51e135ea IZ01433_05.070807.epkg.Z 44750 37 79749e131876794ee5518cfacb5c5fee IZ01433_06.070807.epkg.Z 16878 37 a6badd0df050513eed415c8ff14d8ff0 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 The following options may be used to mitigate the risk posed by this vulnerability in lieu of installing interim fix or APAR. A. OPTION 1 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. All the commands addressed by this advisory can be found in the medium and high fpm databases. B. OPTION 2 Stack execution disable may be enabled on machines running AIX 5.3 TL05 or later. C. OPTION 3 The users may manually remove the SUID bit of these commands mentioned above. Note: Some workarounds may disable functionality for some users. 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 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 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 secure 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 + =========================================================