===================================================================== CERT-Renater Note d'Information No. 2004/VULN191 _____________________________________________________________________ DATE : 29/04/2004 HARDWARE PLATFORM(S) : IBM. OPERATING SYSTEM(S) : AIX 5.1 and 5.2. ====================================================================== IBM SECURITY ADVISORY First Issued: Thu Apr 22 15:17:51 CDT 2004 =========================================================================== VULNERABILITY SUMMARY VULNERABILITY: symlink and buffer overflow vulnerabilities in LVM commands PLATFORMS: AIX 5.1 and 5.2. SOLUTION: Apply the efixes or APARs as described below. THREAT: A local attacker may cause data destruction or a denial of service. A local attacker with system group privileges may execute arbitrary code. CERT VU Number: N/A CVE Number: N/A =========================================================================== DETAILED INFORMATION I. Description =============== A symlink vulnerability was discovered in some LVM commands that allow an attacker to overwrite arbitrary system files. This could lead to data destruction or a denial of service. These issues were discovered internally; at this time there are no known exploits in the wild. Buffer overflow vulnerabilities were discovered in the putlvcb and getlvcb commands. These commands are used by high level LVM commands to modify and query the Logical Volume Control Block. To exploit these issues, an attacker must have system group privileges. There are known exploits for this issue. The commands affected by these issues ship as part of the bos.rte.lvm fileset. To determine if this fileset is installed, execute the following command: # lslpp -L bos.rte.lvm If the fileset is installed it will be listed along with its version information, state, type and a description. II. Impact ========== A local attacker may cause data destruction or a denial of service. A local attacker with system group privileges may execute arbitrary code. III. Solutions =============== A. Official Fix IBM provides the following fixes: APAR number for AIX 5.1.0: IY55681 (available approx. 06/02/04) APAR number for AIX 5.2.0: IY55682 (available approx. 05/19/04) NOTE: Affected customers are urged to upgrade to 5.1.0 or 5.2.0 at the latest maintenance level. B. Emergency Fix Efixes are available for AIX 5.1.0 and 5.2.0. The efixes can be downloaded via ftp from: ftp://aix.software.ibm.com/aix/efixes/security/lvmcmd_efix.tar.Z lvmcmd_efx.tar.Z is a compressed tarball containing this advisory, two efix packages for 5.1.0 and 5.2.0 and cleartext PGP signatures for each efix package. Verify you have retrieved the efixes intact: - - -------------------------------------------- The checksums below were generated using the "sum" and "md5sum" commands and are as follows: Filename sum md5 ====================================================================== lvmcmd51.040422.epkg.Z 20723 485 d6016788254e40377304208870e1e54a lvmcmd52.040422.epkg.Z 49794 542 e5ec42cb05641643fce249663f75f377 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. IMPORTANT: If possible, it is recommended that a mksysb backup of the system is created. Verify it is both bootable, and readable before proceeding. These efixes have not been fully regression tested; thus, IBM does not warrant the fully correct functioning of the efix. Customers install the efix and operate the modified version of AIX at their own risk. Efix Installation Instructions: - - ------------------------------- The efix package for AIX 5.1.0 and 5.2.0 are named lvmcmd51.040422.epkg.Z and lvmcmd52.040422.epkg.Z respectively. These packages use the new Emergency Fix Management Solution to install and manage efixes. More information can be found at: http://techsupport.services.ibm.com/server/aix.efixmgmt To preview an epkg efix installation execute the following command: # emgr -e epkg_name -p # where epkg_name is the name of the # efix package being previewed. To install an epkg efix package, execute the following command: # emgr -e epkg_name -X # where epkg_name is the name of the # efix package being installed. The "X" flag will expand any filesystems if required. IV. Obtaining Fixes =================== AIX Version 5 APARs can be downloaded from the eServer pSeries Fix Central web site: http://www-912.ibm.com/eserver/support/fixes/fcgui.jsp Security related Emergency 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: https://techsupport.services.ibm.com/server/pseries.subscriptionSvcs 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 0x3AE561C3. 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. ====================================================================== ========================================================= 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 + =========================================================