IBM SECURITY ADVISORY First Issued: Mon Sep 12 15:07:01 CDT 2022 |Updated: Mon Dec 12 12:49:47 CST 2022 |Update: Added iFixes for AIX 7.2 TL5 SP5 and VIOS 3.1.4.10. The most recent version of this document is available here: http://aix.software.ibm.com/aix/efixes/security/libxml2_advisory3.asc https://aix.software.ibm.com/aix/efixes/security/libxml2_advisory3.asc ftp://aix.software.ibm.com/aix/efixes/security/libxml2_advisory3.asc Security Bulletin: AIX is vulnerable to a denial of service due to libxml2 (CVE-2022-29824) =============================================================================== SUMMARY: A vulnerability in libxml2 could allow a remote attacker to cause a denial of service (CVE-2022-29824). AIX uses libxml2 as part of its XML parsing functions. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2022-29824 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-29824 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-29824 DESCRIPTION: GNOME libxml2 is vulnerable to a denial of service, caused by an integer overflows in several buffer handling functions in buf.c (xmlBuf*) and tree.c (xmlBuffer*). By persuading a victim to open a specially-crafted XML file, a remote attacker could exploit this vulnerability to cause a denial of service condition. CVSS Base Score: 5.5 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/225645 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 The following fileset levels are vulnerable: key_fileset = aix Fileset Lower Level Upper Level KEY --------------------------------------------------------- bos.rte.control 7.2.4.0 7.2.4.5 key_w_fs | bos.rte.control 7.2.5.0 7.2.5.4 key_w_fs bos.rte.control 7.2.5.100 7.2.5.101 key_w_fs | bos.rte.control 7.2.5.200 7.2.5.200 key_w_fs bos.rte.control 7.3.0.0 7.3.0.1 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.rte.control REMEDIATION: A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR Availability SP KEY ----------------------------------------------------- 7.2.4 IJ42381 ** N/A key_w_apar 7.2.5 IJ42339 ** SP06 key_w_apar 7.3.0 IJ42341 ** SP04 key_w_apar VIOS Level APAR Availability SP KEY ----------------------------------------------------- 3.1.1 IJ42381 ** N/A key_w_apar 3.1.2 IJ42378 ** 3.1.2.60 key_w_apar 3.1.3 IJ42379 ** 3.1.3.40 key_w_apar | 3.1.4 IJ42339 ** 3.1.4.20 key_w_apar Subscribe to the APARs here: http://www.ibm.com/support/pages/apar/IJ42339 http://www.ibm.com/support/pages/apar/IJ42341 http://www.ibm.com/support/pages/apar/IJ42378 http://www.ibm.com/support/pages/apar/IJ42379 http://www.ibm.com/support/pages/apar/IJ42381 https://www.ibm.com/support/pages/apar/IJ42339 https://www.ibm.com/support/pages/apar/IJ42341 https://www.ibm.com/support/pages/apar/IJ42378 https://www.ibm.com/support/pages/apar/IJ42379 https://www.ibm.com/support/pages/apar/IJ42381 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 AIX and VIOS fixes can be downloaded via ftp or http from: ftp://aix.software.ibm.com/aix/efixes/security/libxml2_fix3.tar http://aix.software.ibm.com/aix/efixes/security/libxml2_fix3.tar https://aix.software.ibm.com/aix/efixes/security/libxml2_fix3.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 ---------------------------------------------- 7.2.4.4 IJ42381s6a.220909.epkg.Z key_w_fix 7.2.4.5 IJ42381s6a.220909.epkg.Z key_w_fix 7.2.4.6 IJ42381s6a.220909.epkg.Z key_w_fix 7.2.5.2 IJ42339s2a.220909.epkg.Z key_w_fix 7.2.5.3 IJ42339s4a.220907.epkg.Z key_w_fix 7.2.5.4 IJ42339s4a.220907.epkg.Z key_w_fix | 7.2.5.5 IJ42339s5a.221212.epkg.Z key_w_fix 7.3.0.1 IJ42341s2a.220907.epkg.Z key_w_fix 7.3.0.2 IJ42341s2a.220907.epkg.Z key_w_fix Please note that the above table refers to AIX TL/SP level as opposed to fileset level, i.e., 7.2.5.2 is AIX 7200-05-02. Please reference the Affected Products and Version section above for help with checking installed fileset levels. VIOS Level Interim Fix (*.Z) KEY ----------------------------------------------- 3.1.1.40 IJ42381s6a.220909.epkg.Z key_w_fix 3.1.1.50 IJ42381s6a.220909.epkg.Z key_w_fix 3.1.1.60 IJ42381s6a.220909.epkg.Z key_w_fix 3.1.2.21 IJ42378s2a.220909.epkg.Z key_w_fix | 3.1.2.30 IJ42378s2a.221010.epkg.Z key_w_fix | 3.1.2.40 IJ42378s2a.221010.epkg.Z key_w_fix 3.1.3.10 IJ42379s4a.220909.epkg.Z key_w_fix 3.1.3.14 IJ42379s4a.220909.epkg.Z key_w_fix 3.1.3.21 IJ42379s4a.220909.epkg.Z key_w_fix | 3.1.4.10 IJ42339s5a.221212.epkg.Z key_w_fix To extract the fixes from the tar file: tar xvf libxml2_fix3.tar cd libxml2_fix3 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 ----------------------------------------------------------------------------------------------------- f6d71f263ee414469dde9e6c3325fbc56031d3098ee8831f330e90c9e6b4dd9a IJ42339s2a.220909.epkg.Z key_w_csum 062b34620bc669451695f0de09580aef6e16f36f6430654dee5c403d23bc2fcc IJ42339s4a.220907.epkg.Z key_w_csum | 6a76b4c66b2ff7022b6a00eb2348b4c930af7293692631367f08e4bc65a753df IJ42339s5a.221212.epkg.Z key_w_csum 562b5f19d4db9e4c8835fd92f2e65038c2d765f0ff5e3ef40bad2d9110403a26 IJ42341s2a.220907.epkg.Z key_w_csum f5ec81e718eef7d02adfb85a70f626073f684b93d72173212ba5675fe1eff001 IJ42378s2a.220909.epkg.Z key_w_csum | 6d32716245fee8bc45fb961754eb53aaabc8630eb1e999c1e67cee237cc058cd IJ42378s2a.221010.epkg.Z key_w_csum e00696e638622f82a2264b994fff9415b55c323a271da4c4bb84626046aa031c IJ42379s4a.220909.epkg.Z key_w_csum f03c422e62ea819fa2dfc56342a16da80d20df4444667c6fae97ae95c1c2f6dd IJ42381s6a.220909.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: http://aix.software.ibm.com/aix/efixes/security/libxml2_advisory3.asc.sig https://aix.software.ibm.com/aix/efixes/security/libxml2_advisory3.asc.sig ftp://aix.software.ibm.com/aix/efixes/security/libxml2_advisory3.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: http://www14.software.ibm.com/webapp/set2/sas/f/aix.efixmgmt/home.html 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 To view previously issued advisories, please visit: http://www14.software.ibm.com/webapp/set2/subscriptions/onvdq Contact IBM Support for questions related to this announcement: http://ibm.com/support/ https://ibm.com/support/ To obtain the OpenSSL public key that can be used to verify the signed advisories and ifixes: Download the key from our web page: ftp://ftp.software.ibm.com/systems/power/AIX/systems_p_os_aix_security_pubkey.txt 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-2022-29824) https://www.ibm.com/support/pages/node/6619729 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Mon Sep 12 15:07:01 CDT 2022 | Updated: Mon Oct 10 14:29:18 CDT 2022 | Update: Corrected the affected upper fileset levels for VIOS 3.1.2.30 and | 3.1.2.40. Added iFixes with the correct prereqs for VIOS 3.1.2.30 and | 3.1.2.40. | Updated: Mon Dec 12 12:49:47 CST 2022 | Update: Added iFixes for AIX 7.2 TL5 SP5 and VIOS 3.1.4.10. =============================================================================== *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.