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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2006.0694 -- [AIX] Vulnerability in /etc/slip.login may allow for arbitrary command execution 26 September 2006 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: /etc/slip.login 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: Tue Sep 26 10:00:16 CDT 2006 ========================================================================== VULNERABILITY SUMMARY VULNERABILITY: A vulnerability in /etc/slip.login will allow a local user to execute arbitrary code 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 may execute arbitrary code with root privileges. CERT VU Number: n/a CVE Number: n/a ========================================================================= DETAILED INFORMATION I. Description =============== A security vulnerability in /etc/slip.login may allow a local user to execute arbitrary code with root privileges. /etc/slip.login is an initialization script used when converting a standard-input terminal line into a Serial Line Internet Protocol (SLIP) link to a remote host. /etc/slip.login ships as part of the bos.net.tcp.client fileset. To determine if a fileset is installed, execute the following command: # lslpp -L bos.net.tcp.client The fileset will be listed along with its version information, state, type and a description. The following table shows the vulnerable versions of bos.net.tcp.client. AIX Release Lower Upper Level Level =========================================== AIX 5.2 5.2.0.0 5.2.0.95 AIX 5.3 5.3.0.0 5.3.0.51 II. Impact ========== A local user may execute arbitrary commands with root privileges. III. Solutions =============== A. Official Fix IBM provides the following fixes: APAR number for AIX 5.2.0: IY88566 (available) APAR number for AIX 5.3.0: IY88615 (available approx. 10/04/06) NOTE: Affected customers are urged to upgrade to the latest applicable Technology Level. B. Interim Fix Interim fixes are available. The ifixes can be downloaded via ftp from: ftp://aix.software.ibm.com/aix/efixes/security/sliplogin_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 ========================================================================= IY88566_07.091906.epkg.Z 35585 4 c1a39db8ecfb9fb88b92a5d952558310 IY88566_08.091906.epkg.Z 64356 4 459ee16f1691c8463953fec7719eaaa8 IY88566_09.091906.epkg.Z 05225 4 a3362556c84c49f3ad822f3ab9ba2b09 IY88615_03.091906.epkg.Z 02913 4 b07f0d45d63eb51552ef7fc771d92fa8 IY88615_04.091906.epkg.Z 30678 4 d774af099011d7eee81e28acf976671f IY88615_05.091906.epkg.Z 15527 4 dda945164ca8ff89a45670339a95aeba 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.client. Interim Fileset Level Fileset Level Fix (lower limit) (upper limit) =================================================================== IY88566_07.091906.epkg.Z 5.2.0.75 5.2.0.77 IY88566_08.091906.epkg.Z 5.2.0.85 5.2.0.88 IY88566_09.091906.epkg.Z 5.2.0.95 5.2.0.95 IY88615_03.091906.epkg.Z 5.3.0.30 5.3.0.32 IY88615_04.091906.epkg.Z 5.3.0.40 5.3.0.44 IY88615_05.091906.epkg.Z 5.3.0.50 5.3.0.51 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 ifixes. More information can be found at: http://www14.software.ibm.com/webapp/set2/sas/f/aix.efixmgmt/home.html 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 Remove the setuid bit from /usr/sbin/sliplogin. This can be done as follows: # chmod 555 /usr/sbin/sliplogin Verify the changes: # ls -la /usr/sbin/sliplogin - - -r-xr-xr-x 1 root system 15388 Aug 8 14:28 /usr/sbin/sliplogin Note that this may prevent sliplogin from functioning normally for non-root users. 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) iD8DBQFFErKpofN/JhsU8pkRAt0KAJ9mfbLobrZvbBYG/Xok82FDDMvumQCeOnpW SqLkD2+moZZLX6/JF2Pl6bQ= =DLry - -----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. 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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 iQCVAwUBRRiWACh9+71yA2DNAQKYCwP+LSj+u/UqgZ6rUGGfHw6vo6gfdbFR+4+R hdbMJQlsnxaFZrfHE6xPi1wfExHZkBj5pbBQ63h/OrEMlLHPZLgPl7wMCeinkZjH 5hhsgwav3lY7hVlqMVwxEFEhNOUtblqcl9pVGe1x7Xsh8FaVF/B1QDcQseGPXT6V 3us7hOC6SrA= =L+7Y -----END PGP SIGNATURE-----