IBM SECURITY ADVISORY First Issued: Wed May 8 16:18:28 CDT 2024 |Updated: Tue Jun 4 15:20:02 CDT 2024 |Update: iFix added for VIOS 3.1.4.31. The most recent version of this document is available here: https://aix.software.ibm.com/aix/efixes/security/libxml2_advisory6.asc Security Bulletin: AIX is vulnerable to a denial of service due to libxml2 (CVE-2024-25062) =============================================================================== SUMMARY: Vulnerability in libxml2 could allow a remote attacker to cause a denial of service (CVE-2024-25062). AIX uses libxml2 as part of its XML parsing functions. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2024-25062 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-25062 DESCRIPTION: GNOME libxml2 is vulnerable to a denial of service, caused by a use-after-free flaw in the xmlValidatePopElement() function. By persuading a victim to open a specially crafted content, a remote attacker could exploit this vulnerability to cause the application to crash. CVSS Base Score: 5.5 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/281615 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H) AFFECTED PRODUCTS AND VERSIONS: AIX 7.2, 7.3 VIOS 3.1, 4.1 The following fileset levels are vulnerable: key_fileset = aix Fileset Lower Level Upper Level KEY --------------------------------------------------------- bos.rte.control 7.2.5.0 7.2.5.102 key_w_fs bos.rte.control 7.2.5.200 7.2.5.202 key_w_fs bos.rte.control 7.3.0.0 7.3.0.3 key_w_fs bos.rte.control 7.3.1.0 7.3.1.2 key_w_fs bos.rte.control 7.3.2.0 7.3.2.0 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.rte.control REMEDIATION: A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR Availability SP KEY ----------------------------------------------------- 7.2.5 IJ50602 ** SP08 key_w_apar 7.3.0 IJ50827 ** N/A key_w_apar 7.3.1 IJ50635 ** SP04 key_w_apar 7.3.2 IJ50601 ** SP02 key_w_apar VIOS Level APAR Availability SP KEY ----------------------------------------------------- 3.1.3 IJ50828 ** N/A key_w_apar 3.1.4 IJ50602 ** 3.1.4.40 key_w_apar 4.1.0 IJ50601 ** 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. The fixes are cumulative and address previously issued AIX/VIOS libxml2 security bulletins with respect to SP and TL: https://aix.software.ibm.com/aix/efixes/security/libxml2_advisory5.asc https://www.ibm.com/support/pages/node/7014485 https://aix.software.ibm.com/aix/efixes/security/libxml2_advisory4.asc https://www.ibm.com/support/pages/node/6953825 https://aix.software.ibm.com/aix/efixes/security/libxml2_advisory3.asc https://www.ibm.com/support/pages/node/6619729 The AIX and VIOS fixes can be downloaded via https from: https://aix.software.ibm.com/aix/efixes/security/libxml2_fix6.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 IJ50602m7a.240409.epkg.Z key_w_fix 7.2.5.6 IJ50602m7a.240409.epkg.Z key_w_fix 7.2.5.7 IJ50602m7a.240409.epkg.Z key_w_fix 7.3.0.2 IJ50827m4a.240409.epkg.Z key_w_fix 7.3.0.3 IJ50827m4a.240409.epkg.Z key_w_fix 7.3.0.4 IJ50827m4a.240409.epkg.Z key_w_fix 7.3.1.1 IJ50635m3a.240409.epkg.Z key_w_fix 7.3.1.2 IJ50635m3a.240409.epkg.Z key_w_fix 7.3.1.3 IJ50635m3a.240409.epkg.Z key_w_fix 7.3.2.1 IJ50601s1a.240409.epkg.Z key_w_fix Please note that the above table refers to AIX TL/SP level as opposed to fileset level, i.e., 7.3.0.3 is AIX 7300-00-03. 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 IJ50828m4a.240409.epkg.Z key_w_fix 3.1.3.30 IJ50828m4a.240409.epkg.Z key_w_fix 3.1.3.40 IJ50828m4a.240409.epkg.Z key_w_fix | 3.1.4.10 IJ50602m7a.240409.epkg.Z key_w_fix 3.1.4.21 IJ50602m7a.240409.epkg.Z key_w_fix | 3.1.4.31 IJ50602m7a.240409.epkg.Z key_w_fix 4.1.0.10 IJ50601s1a.240409.epkg.Z key_w_fix To extract the fixes from the tar file: tar xvf libxml2_fix6.tar cd libxml2_fix6 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 ----------------------------------------------------------------------------------------------------- 8bf16c8c98877439c134f7a21a326c60c2f5ba8633d2e23deb4801e64a073a4b IJ50601s1a.240409.epkg.Z key_w_csum a921435fa369cd5fd6b96e8d2e3852ca1970e06d393f5467c8ca02b64e1141d6 IJ50602m7a.240409.epkg.Z key_w_csum c72a6348bf978e83a5c3a9d40fa0fe3f6f7a1cf95f70c99bd31085dda758ca99 IJ50635m3a.240409.epkg.Z key_w_csum d9d38426769f7fd01c46ff7c71576feef3cecdbcc2a50a590dd35b0112d90ab2 IJ50827m4a.240409.epkg.Z key_w_csum 63353f135b6a41a5d8e35fd0873f032e378273453257b504be09ee20930f376f IJ50828m4a.240409.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/libxml2_advisory6.asc.sig C. FIX AND INTERIM FIX INSTALLATION 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/libxml2_advisory6.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 a denial of service due to libxml2 (CVE-2024-25062) https://www.ibm.com/support/pages/node/7150641 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Wed May 8 16:18:28 CDT 2024 | Updated: Tue Jun 4 15:20:02 CDT 2024 | Update: iFix added for VIOS 3.1.4.31. =============================================================================== *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.