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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2006.0701 -- [AIX] Vulnerability in named8 may allow for arbitrary command execution 27 September 2006 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: named8 Publisher: IBM Operating System: AIX 5.3 AIX 5.2 Impact: Root Compromise Access: Existing Account - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 IBM SECURITY ADVISORY First Issued: Mon Sep 25 10:00 CDT 2006 ========================================================================== VULNERABILITY SUMMARY VULNERABILITY: A vulnerability in named8 may allow a user in the system group to execute arbitrary commands with root privileges. PLATFORMS: AIX 5.2 and 5.3. SOLUTION: Apply the APAR, interim fix or workaround as described below. THREAT: A local user in the system group may execute arbitrary commands as root CERT VU Number: n/a CVE Number: n/a ========================================================================== DETAILED INFORMATION I. Description =============== Berkeley Internet Name Domain 8 (BIND 8) is a Domain Name System (DNS) distribution from the Internet Systems Consortium (ISC) and it is included with AIX 5.2 and 5.3. A security vulnerability was discovered in named8 which may allow a local user in the system group to execute arbitrary code with root privileges. named8 ships as part of the bos.net.tcp.server fileset. To determine if this fileset is installed, execute the following command: # lslpp -L bos.net.tcp.server If the fileset is installed it will be listed along with its version information, state, type and a description. The following table shows the vulnerable versions of bos.net.tcp.server. AIX Release Lower Upper Level Level =========================================== AIX 5.2 5.2.0.0 5.2.0.85 AIX 5.3 5.3.0.0 5.3.0.40 II. Impact ========== A local user in the system group may execute arbitrary commands with root privileges. III. Solutions =============== A. APARs IBM provides the following fixes: APAR number for AIX 5.2.0: IY76102 (available) APAR number for AIX 5.3.0: IY76483 (available) NOTE: Affected customers are urged to upgrade to the latest applicable Technology Level. B. Interim Fix Interim fixes are available. The interim fixes can be downloaded via ftp from: ftp://aix.software.ibm.com/aix/efixes/security/named8_ifix.tar.Z This is a compressed tarball containing this advisory, interim fix packages and cleartext PGP signatures for each package. Verify you have retrieved the fixes intact: +------------------------------------------ The interim fixes below are named by using the APAR corresponding to the release that the fix applies to. The APAR is followed by an underscore and the Technology Level for the particular AIX release that a fix applies to. The checksums below were generated using the "sum" and "md5sum" commands and are as follows: The interim fixes below include prerequisite checking. This will enforce the correct mapping between the fixes and AIX Technology Levels. Filename sum md5 ========================================================================= IY76102_07.060824.epkg.Z 22728 471 2784cfd2c0437216f3222dd11b971840 IY76102_08.060824.epkg.Z 16675 472 7bc52f632c7880c50c54690bbde0d497 IY76483_03.060824.epkg.Z 37314 463 7c9480925cc629303f555609059602eb IY76483_04.060824.epkg.Z 09427 465 d6ed5bacfbc2b194ea832a08f6cd3da6 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. The interim fixes include prerequisite checking. This will ensure the correct mapping between the interim fixes and AIX Technology Levels. The following table shows the prerequisite fileset levels required for the fixes above. The fileset levels listed are for bos.net.tcp.server. Interim Fileset Level Fileset Level Fix (lower limit) (upper limit) =================================================================== IY76102_07.060824.epkg.Z 5.2.0.76 5.2.0.76 IY76102_08.060824.epkg.Z 5.2.0.85 5.2.0.85 IY76483_03.060824.epkg.Z 5.3.0.30 5.3.0.30 IY76483_04.060824.epkg.Z 5.3.0.40 5.3.0.40 IMPORTANT: If possible, it is recommended that a mksysb backup of the system is created. Verify it is both bootable, and readable before proceeding. Customers may contact IBM support if any issues arise with these interim fixes. Interim Installation Instructions: +--------------------------------- 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. C. Workaround Remove the setuid root bit. Note that this will prevent named8 from functioning normally for non-root users. This can be done by executing the following command: # chmod 550 /usr/sbin/named8 Verify the changes: # ls -la /usr/sbin/named8 - - -r-xr-x--- 1 root system 649070 Nov 23 2004 /usr/sbin/named8 Restart named8 after applying this interim fix. IV. 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 V. 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 0x1B14F299. 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 v1.4.3 (GNU/Linux) iD8DBQFFEt0JofN/JhsU8pkRAnmLAJ9IVrnDmrwu+c9aH3wFIneAD6aUkACeOtdt BWM+i0qtGX3ZuIsT2pcs1H4= =ky9s - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. 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Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 If you believe that your computer system has been compromised or attacked in any way, we encourage you to let us know by completing the secure National IT Incident Reporting Form at: http://www.auscert.org.au/render.html?it=3192 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQCVAwUBRRnDPih9+71yA2DNAQLVlQP/R8uVhEzQOEs2sKyRPREANS1JwlTatZAF Jkd7LaISo71BaH+mo4UpV0OFeqad8bTSiHSHWaAXpBflbfofUBVez1wCM3v0jYTi t4qpPgvWjcIPqQryHWaLCDux7hUmZEYuhcu/cEj+E/U3dptmZtOvFzdSxmKNnQW3 2MZYUHvyReg= =vlSB -----END PGP SIGNATURE-----