IBM SECURITY ADVISORY First Issued: Mon May 6 08:12:16 CDT 2024 The most recent version of this document is available here: https://aix.software.ibm.com/aix/efixes/security/kernel_advisory7.asc Security Bulletin: AIX is vulnerable to privilege escalation (CVE-2024-27273) =============================================================================== SUMMARY: Vulnerability in the AIX kernel may lead to privilege escalation (CVE-2024-27273). =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2024-27273 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-27273 DESCRIPTION: IBM AIX's Unix domain datagram socket implementation could potentially expose applications using Unix domain datagram sockets with SO_PEERID operation and may lead to privilege escalation. CVSS Base Score: 8.1 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/284903 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H) AFFECTED PRODUCTS AND VERSIONS: AIX 7.2, 7.3 VIOS 3.1, 4.1 The vulnerabilities in the following filesets are being addressed: key_fileset = aix Fileset Lower Level Upper Level KEY --------------------------------------------------------- bos.mp64 7.2.5.0 7.2.5.107 key_w_fs bos.mp64 7.2.5.200 7.2.5.205 key_w_fs bos.mp64 7.3.0.0 7.3.0.5 key_w_fs bos.mp64 7.3.1.0 7.3.1.4 key_w_fs bos.mp64 7.3.2.0 7.3.2.1 key_w_fs To find out whether the affected filesets are installed on your systems, refer to the lslpp command found in AIX user's guide. Example: lslpp -L | grep -i bos.mp64 REMEDIATION: A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR Availability SP KEY ----------------------------------------------------- 7.2.5 IJ50910 ** SP08 key_w_apar 7.3.0 IJ50936 ** N/A key_w_apar 7.3.1 IJ50935 ** SP04 key_w_apar 7.3.2 IJ50934 ** SP02 key_w_apar VIOS Level APAR Availability SP KEY ----------------------------------------------------- 3.1.3 IJ50937 ** N/A key_w_apar 3.1.4 IJ50910 ** 3.1.4.40 key_w_apar 4.1.0 IJ50934 ** 4.1.0.20 key_w_apar Subscribe to the APARs here: https://www.ibm.com/support/pages/apar/[APAR Number] By subscribing, you will receive periodic email alerting you to the status of the APAR, and a link to download the fix once it becomes available. B. FIXES IBM strongly recommends addressing the vulnerability now. AIX and VIOS fixes are available. An LPAR system reboot is required to complete the iFix installation, or Live Update may be used on AIX 7.2 and 7.3 to avoid a reboot. The AIX and VIOS fixes can be downloaded via https from: https://aix.software.ibm.com/aix/efixes/security/kernel_fix7.tar The link above is to a tar file containing this signed advisory, fix packages, and OpenSSL signatures for each package. The fixes below include prerequisite checking. This will enforce the correct mapping between the fixes and AIX Technology Levels. AIX Level Interim Fix (*.Z) KEY ---------------------------------------------- 7.2.5.5 IJ50910m5a.240502.epkg.Z key_w_fix 7.2.5.6 IJ50910m6a.240502.epkg.Z key_w_fix 7.2.5.7 IJ50910s7a.240418.epkg.Z key_w_fix 7.3.0.2 IJ50936m2a.240502.epkg.Z key_w_fix 7.3.0.3 IJ50936m3a.240502.epkg.Z key_w_fix 7.3.0.4 IJ50936m4a.240502.epkg.Z key_w_fix 7.3.1.1 IJ50935m1a.240502.epkg.Z key_w_fix 7.3.1.2 IJ50935m2a.240502.epkg.Z key_w_fix 7.3.1.3 IJ50935s3a.240418.epkg.Z key_w_fix 7.3.2.1 IJ50934s1a.240418.epkg.Z key_w_fix Please note that the above table refers to AIX TL/SP level as opposed to fileset level, i.e., 7.2.5.6 is AIX 7200-05-06. Please reference the Affected Products and Version section above for help with checking installed fileset levels. VIOS Level Interim Fix (*.Z) KEY ----------------------------------------------- 3.1.3.21 IJ50937m2a.240502.epkg.Z key_w_fix 3.1.3.30 IJ50937m3a.240502.epkg.Z key_w_fix 3.1.3.40 IJ50937m4a.240502.epkg.Z key_w_fix 3.1.4.10 IJ50910m5a.240502.epkg.Z key_w_fix 3.1.4.21 IJ50910m6a.240502.epkg.Z key_w_fix 3.1.4.31 IJ50910s7a.240418.epkg.Z key_w_fix 4.1.0.10 IJ50934s1a.240418.epkg.Z key_w_fix The fixes are cumulative and address previously issued AIX/VIOS kernel security and HIPER bulletins with respect to SP and TL, which includes: https://aix.software.ibm.com/aix/efixes/security/kernel_advisory6.asc https://www.ibm.com/support/pages/node/7105282 https://www.ibm.com/support/pages/node/6857545 https://aix.software.ibm.com/aix/efixes/security/kernel_advisory5.asc https://www.ibm.com/support/pages/node/6847947 To extract the fixes from the tar file: tar xvf kernel_fix7.tar cd kernel_fix7 Verify you have retrieved the fixes intact: The checksums below were generated using the "openssl dgst -sha256 [filename]" command as the following: openssl dgst -sha256 filename KEY ----------------------------------------------------------------------------------------------------- 20e7f9984bd3f82f0edf2523e039476c35a9b5ee19ce642524205cc078f37df2 IJ50910m5a.240502.epkg.Z key_w_csum 26ada723ea3ecde12c83b04a8f2266d518bbf282a8dcec8972b9947d46b1d341 IJ50910m6a.240502.epkg.Z key_w_csum 6ce0cc7acef1e5cc4f27493e49d7d5687d1b111eaaf1bf161b88a41fe88f022f IJ50910s7a.240418.epkg.Z key_w_csum e604f15538d68688dadff227c822c01c488884865b9d9a9c3567ce4f098b90ec IJ50934s1a.240418.epkg.Z key_w_csum f7d5ecde8c0e146c164c65bc77ca3a15144d2132eeba269dd5ecb880a9e94734 IJ50935m1a.240502.epkg.Z key_w_csum cebad1156c081a9345374db95c8533799fcd7fe1c95f16faeb97f01fddda9946 IJ50935m2a.240502.epkg.Z key_w_csum fbc7cad5e854772fce7e5cd2426e7c653f6ae2cc9ecff3735c14c63a0c41c96d IJ50935s3a.240418.epkg.Z key_w_csum 953c8c96ed53f202a03c8c044d72e64b8778e6cd4a4e60dcd34ff904dcaa0c99 IJ50936m2a.240502.epkg.Z key_w_csum c97fb2d06e6efbca162134292e242aa5892c7bc3fbeae72b675ff8b6d4361c4a IJ50936m3a.240502.epkg.Z key_w_csum 691164620d96cb9e353aba78f5a8ca288ab625efca6bc536052b163b1f3c15e1 IJ50936m4a.240502.epkg.Z key_w_csum 06709014779183f1a204228724aa439401b14d13c2a9d55300bf8d91d138754c IJ50937m2a.240502.epkg.Z key_w_csum bf7e6ee7afdec2fa58662ce973fe4f7903446b20219463174d5bd4b3b031b40b IJ50937m3a.240502.epkg.Z key_w_csum 03d7ad9b0fc0dfad5862060140d1a5b926539c7e91fb9c6b157f2fc83a154ae9 IJ50937m4a.240502.epkg.Z key_w_csum These sums should match exactly. The OpenSSL signatures in the tar file and on this advisory can also be used to verify the integrity of the fixes. If the sums or signatures cannot be confirmed, contact IBM Support at http://ibm.com/support/ and describe the discrepancy. openssl dgst -sha256 -verify [pubkey_file] -signature [advisory_file].sig [advisory_file] openssl dgst -sha256 -verify [pubkey_file] -signature [ifix_file].sig [ifix_file] Published advisory OpenSSL signature file location: https://aix.software.ibm.com/aix/efixes/security/kernel_advisory7.asc.sig C. FIX AND INTERIM FIX INSTALLATION An LPAR system reboot is required to complete the iFix installation, or Live Update may be used on AIX 7.2 and 7.3 to avoid a reboot. If possible, it is recommended that a mksysb backup of the system be created. Verify it is both bootable and readable before proceeding. To preview a fix installation: installp -a -d fix_name -p all # where fix_name is the name of the # fix package being previewed. To install a fix package: installp -a -d fix_name -X all # where fix_name is the name of the # fix package being installed. Interim fixes have had limited functional and regression testing but not the full regression testing that takes place for Service Packs; however, IBM does fully support them. Interim fix management documentation can be found at: https://www.ibm.com/support/pages/managing-interim-fixes-aix To preview an interim fix installation: emgr -e ipkg_name -p # where ipkg_name is the name of the # interim fix package being previewed. To install an interim fix package: emgr -e ipkg_name -X # where ipkg_name is the name of the # interim fix package being installed. WORKAROUNDS AND MITIGATIONS: None. =============================================================================== CONTACT US: Note: Keywords labeled as KEY in this document are used for parsing purposes. If you would like to receive AIX Security Advisories via email, please visit "My Notifications": http://www.ibm.com/support/mynotifications Contact IBM Support for questions related to this announcement: https://ibm.com/support/ For information on how to securely verify AIX security bulletins and fixes: https://www.ibm.com/support/pages/node/6985269 To obtain the OpenSSL public key that can be used to verify the signed advisories and ifixes: Download the key from our web page: https://aix.software.ibm.com/aix/efixes/security/systems_p_os_aix_security_pubkey.txt To verify the AIX/VIOS security bulletin: Published advisory OpenSSL signature file location: https://aix.software.ibm.com/aix/efixes/security/kernel_advisory7.asc.sig openssl dgst -sha256 -verify [pubkey_file] -signature [advisory_file].sig [advisory_file] Please contact your local IBM AIX support center for any assistance. REFERENCES: Complete CVSS v3 Guide: http://www.first.org/cvss/user-guide On-line Calculator v3: http://www.first.org/cvss/calculator/3.0 RELATED INFORMATION: IBM Secure Engineering Web Portal http://www.ibm.com/security/secure-engineering/bulletins.html IBM Product Security Incident Response Blog https://www.ibm.com/blogs/psirt/ Security Bulletin: AIX is vulnerable to privilege escalation (CVE-2024-27273) https://www.ibm.com/support/pages/node/7150297 ACKNOWLEDGEMENTS: The vulnerability was reported to IBM by Christian Kohlschuetter. CHANGE HISTORY: First Issued: Mon May 6 08:12:16 CDT 2024 =============================================================================== *The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin. Disclaimer According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES "AS IS" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY.