Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2005.0991 -- [AIX] Buffer overflow vulnerability in slocal 16 December 2005 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: slocal Publisher: IBM Operating System: AIX Impact: Root Compromise Access: Existing Account - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 IBM SECURITY ADVISORY First Issued: Thu Dec 15 09:00:44 CST 2005 ========================================================================== VULNERABILITY SUMMARY VULNERABILITY: A buffer overflow vulnerability in slocal may allow any local user to gain root privileges. PLATFORMS: AIX 5.1, 5.2 and 5.3. SOLUTION: Apply the APAR, interim fix or workaround as described below. THREAT: A local user may gain root privileges. CERT VU Number: N/A CVE Number: N/A ========================================================================= DETAILED INFORMATION I. Description =============== A buffer overflow vulnerability in slocal may allow any local user to gain root privileges. The slocal command is used to perform various actions when mail is received for a user. The command affected by this issue ships as part of the bos.mh fileset. To determine if this fileset is installed, execute the following command: # lslpp -L bos.mh If the fileset is installed it will be listed along with its version information, state, type and a description. II. Impact ========== A local user may gain root privileges. III. Solutions =============== A. Official Fix IBM provides the following fixes: APAR number for AIX 5.1.0: IY78224 (available approx. 01/30/06) APAR number for AIX 5.2.0: IY78225 (available approx. 01/30/06) APAR number for AIX 5.3.0: IY78226 (available approx. 01/30/06) NOTE: Affected customers are urged to upgrade to 5.1.0, 5.2.0 or 5.3.0 at the latest maintenance level. B. Interim Fix Interim fixes are available for AIX 5.1.0, 5.2.0 and 5.3.0. The ifixes can be downloaded via ftp from: ftp://aix.software.ibm.com/aix/efixes/security/slocal_ifix.tar.Z slocal_ifix.tar.Z is a compressed tarball containing this advisory, ifix packages and cleartext PGP signatures for each ifix 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 maintenance 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: Filename sum md5 ======================================================================== IY78224_09.051030.epkg.Z 40220 42 c87ca388a41a6c6b5463ceaac0281477 IY78225_05.051030.epkg.Z 03039 40 36e272bed902efc571c6081fb2181100 IY78225_06.051030.epkg.Z 33105 40 20085be1b87209c4d8aa947b26ea508e IY78225_07.051030.epkg.Z 27898 40 f435b1d6289ff3149baab5e871b9a21b IY78226_01.051030.epkg.Z 23364 40 32cc3c485e9cff7c2174155885a84cae IY78226_02.051030.epkg.Z 52233 40 b0fe8a00a26e8a2738bb50676861a6de IY78226_03.051030.epkg.Z 20347 40 27dca198577a8eaf242649738ef2c896 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 ifixes have not been fully regression tested; thus, IBM does not warrant the fully correct functioning of the ifix. Customers install the ifix and operate the modified version of AIX at their own risk. Interim Installation Instructions: - - ---------------------------------- These packages use the new Interim Fix Management Solution to install and manage ifixes. More information can be found at: http://techsupport.services.ibm.com/server/aix.efixmgmt To preview an epkg ifix installation execute the following command: # emgr -e ipkg_name -p # where ipkg_name is the name of the # ifix package being previewed. To install an epkg ifix package, execute the following command: # emgr -e ipkg_name -X # where ipkg_name is the name of the # ifix package being installed. The "X" flag will expand any filesystems if required. C. Workaround Remote the setuid file mode bit - - ------------------------------- Removing the setuid root file mode bit will prevent non-root users from exploiting the vulnerability. To remove the setuid bit, execute the following command: # chmod 555 /usr/lib/mh/slocal Verify that the file mode bits have been updated: # ls -la /usr/lib/mh/slocal - - -r-xr-xr-x 1 root bin 85304 Apr 10 2005 /usr/lib/mh/slocal sendmail starts slocal if a user's .forward file contains "/usr/lib/mh/slocal". If slocal is not used, the suidroot bit can be safely removed. IV. Obtaining Fixes =================== AIX Version 5 APARs can be downloaded from: http://www-1.ibm.com/servers/eserver/support/pseries/aixfixes.html Security related Interim Fixes can be downloaded from: ftp://aix.software.ibm.com/aix/efixes/security V. Acknowledgments ================== This vulnerability was reported by David Litchfield of NGS Software. VI. 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 0x9391C1F2. 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 v1.4.1 (GNU/Linux) iD8DBQFDnxihxwSSvpORwfIRArVAAJ903xGHHbkN4iesynhyfOsvTjj6uQCfZlMw NWG779qteOd9KQ3jdMhUFns= =f87m - -----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. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. 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 iQCVAwUBQ6JcYih9+71yA2DNAQKZvgQAgdm/DBcOoFu/h0a+4Kg73VFMccXKUcCs SozPri3O3G0n5vKQgs1n6e7VZtWU5v5Fq5wspR1UmQBeHj6+VXKYegxb2aDXm65Y ufClheLZZIR1n9fS9zMPK9NUf0E3NoF7A/OEn17opD8Pl2mtpddfKJvKLaLiiN1t 3dtRMWo8x6U= =BL10 -----END PGP SIGNATURE-----