IBM SECURITY ADVISORY First Issued: Wed Feb 8 13:18:47 CST 2023 |Updated: Thu May 4 13:36:14 CDT 2023 |Update: Corrected the affected upper fileset levels for AIX 7.2 TL5 to | show that SP06 is affected. Corrected the affected upper fileset | levels for AIX 7.3 TL1 to show that SP02 is affected. Corrected the | affected upper fileset levels for VIOS to show that VIOS 3.1.4.21 | is affected. | Added iFixes for AIX 7.2 TL5 SP06 and 7.3 TL1 SP02. | Added iFix for VIOS 3.1.4.21. The most recent version of this document is available here: https://aix.software.ibm.com/aix/efixes/security/libxml2_advisory4.asc Security Bulletin: AIX is vulnerable to arbitrary code execution due to libxml2 (CVE-2022-40303 and CVE-2022-40304) =============================================================================== SUMMARY: Vulnerabilities in libxml2 could allow a remote attacker to execute arbitrary code (CVE-2022-40303 and CVE-2022-40304). AIX uses libxml2 as part of its XML parsing functions. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2022-40304 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-40304 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-40304 DESCRIPTION: Gnome ibxml2 could allow a remote attacker to execute arbitrary code on the system, caused by a dict corruption flaw. By persuading a victim to open a specially-crafted file, an attacker could exploit this vulnerability to execute arbitrary code on the system. CVSS Base Score: 7.8 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/238603 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) CVEID: CVE-2022-40303 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-40303 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-40303 DESCRIPTION: Gnome libxml2 could allow a remote attacker to execute arbitrary code on the system, caused by an integer overflow in the XML_PARSE_HUGE function. By persuading a victim to open a specially-crafted file, an attacker could exploit this vulnerability to execute arbitrary code on the system. CVSS Base Score: 7.8 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/238602 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/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 7.2.5.0 7.2.5.5 key_w_fs bos.rte.control 7.2.5.100 7.2.5.102 key_w_fs | bos.rte.control 7.2.5.200 7.2.5.201 key_w_fs bos.rte.control 7.3.0.0 7.3.0.2 key_w_fs | bos.rte.control 7.3.1.0 7.3.1.1 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 ----------------------------------------------------- | 7.2.5 IJ45056 ** SP07 key_w_apar 7.3.0 IJ45059 ** SP04 key_w_apar | 7.3.1 IJ45060 ** SP03 key_w_apar VIOS Level APAR Availability SP KEY ----------------------------------------------------- 3.1.2 IJ45057 ** 3.1.2.60 key_w_apar 3.1.3 IJ45058 ** 3.1.3.40 key_w_apar | 3.1.4 IJ45056 ** 3.1.4.30 key_w_apar Subscribe to the APARs here: https://www.ibm.com/support/pages/apar/IJ45056 https://www.ibm.com/support/pages/apar/IJ45057 https://www.ibm.com/support/pages/apar/IJ45058 https://www.ibm.com/support/pages/apar/IJ45059 https://www.ibm.com/support/pages/apar/IJ45060 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_advisory3.asc https://www.ibm.com/support/pages/node/6619729 The AIX and VIOS fixes can be downloaded via ftp or http from: https://aix.software.ibm.com/aix/efixes/security/libxml2_fix4.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 ---------------------------------------------- 7.2.5.3 IJ45056m4a.230125.epkg.Z key_w_fix 7.2.5.4 IJ45056m4a.230125.epkg.Z key_w_fix 7.2.5.5 IJ45056m5a.230125.epkg.Z key_w_fix | 7.2.5.6 IJ45056m6a.230504.epkg.Z key_w_fix 7.3.0.1 IJ45059m2a.230125.epkg.Z key_w_fix 7.3.0.2 IJ45059m2a.230125.epkg.Z key_w_fix | 7.3.0.3 IJ45059m2b.230405.epkg.Z key_w_fix 7.3.1.1 IJ45060s1a.230125.epkg.Z key_w_fix | 7.3.1.2 IJ45060s2a.230504.epkg.Z key_w_fix Please note that the above table refers to AIX TL/SP level as opposed to fileset level, i.e., 7.2.5.4 is AIX 7200-05-04. Please reference the Affected Products and Version section above for help with checking installed fileset levels. VIOS Level Interim Fix (*.Z) KEY ----------------------------------------------- 3.1.2.21 IJ45057m2a.230125.epkg.Z key_w_fix 3.1.2.30 IJ45057m2a.230125.epkg.Z key_w_fix 3.1.2.40 IJ45057m2a.230125.epkg.Z key_w_fix | 3.1.2.50 IJ45057m2b.230405.epkg.Z key_w_fix 3.1.3.10 IJ45058m4a.230125.epkg.Z key_w_fix 3.1.3.14 IJ45058m4a.230125.epkg.Z key_w_fix 3.1.3.21 IJ45058m4a.230125.epkg.Z key_w_fix | 3.1.3.30 IJ45058m4b.230405.epkg.Z key_w_fix 3.1.4.10 IJ45056m5a.230125.epkg.Z key_w_fix | 3.1.4.21 IJ45056m6a.230504.epkg.Z key_w_fix To extract the fixes from the tar file: tar xvf libxml2_fix4.tar cd libxml2_fix4 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 ----------------------------------------------------------------------------------------------------- 4e9fac76175c05897451d9a3c565ba3788e268f8138a8b943f979b1c12b6740b IJ45056m4a.230125.epkg.Z key_w_csum 8bb8a20bca4cd2d1c53bf70b757eda71a93754b9312002f3b2541bfd624f4092 IJ45056m5a.230125.epkg.Z key_w_csum ddcf3bf894f78b0d42296a99e7535ec9476092a49bb54d27a58991626e10c79f IJ45057m2a.230125.epkg.Z key_w_csum 11f90b34631af383a76be21b9934b708b69cc2e9255d9885a94ce9694861d540 IJ45058m4a.230125.epkg.Z key_w_csum 04a8cb93965ed8a85c759f7239e76691a415e7d1b6f3eba30f60c6b59327547a IJ45059m2a.230125.epkg.Z key_w_csum bcfacf870805a4be290349715f6b61f0766cf3998d53bf638995b2f2f4367601 IJ45060s1a.230125.epkg.Z key_w_csum | d5fd7c9723ad2da2eaccf8475b42c40867936cd2a0a3672851408157bf028453 IJ45058m4b.230405.epkg.Z key_w_csum | efb86d3a27e18ee2798c636192eddd4c56fe2ca173d88d879e612206e5b6dd65 IJ45057m2b.230405.epkg.Z key_w_csum | e2e155fefbdb3a2927d9e7e0468af61c0e685264566247ddc12e860f8b045be1 IJ45059m2b.230405.epkg.Z key_w_csum | e37dad7bb93f9853ac544a28db0c0f7cf6c03e79e19d96421f44a278c16ab2fc IJ45056m6a.230504.epkg.Z key_w_csum | 71cd144588dbcbcd422e7bfdd5b1feee6bd5bb13c7727297f6f3fe708b3dc15d IJ45060s2a.230504.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_advisory4.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 arbitrary code execution due to libxml2 (CVE-2022-40303 and CVE-2022-40304) https://www.ibm.com/support/pages/node/6953825 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Wed Feb 8 13:18:47 CST 2023 | Updated: Wed Apr 5 14:42:23 CDT 2023 | Update: Corrected the affected upper fileset levels for AIX 7.3 TL0 to | show that SP03 is affected. Corrected the affected upper fileset | levels for VIOS to show that VIOS 3.1.2.50 and 3.1.3.30 are affected. | Added iFixes for AIX 7.3 TL0 SP03 and VIOS 3.1.2.50 and 3.1.3.30. | Updated: Thu May 4 13:36:14 CDT 2023 | Update: Corrected the affected upper fileset levels for AIX 7.2 TL5 to | show that SP06 is affected. Corrected the affected upper fileset | levels for AIX 7.3 TL1 to show that SP02 is affected. Corrected the | affected upper fileset levels for VIOS to show that VIOS 3.1.4.21 | is affected. | Added iFixes for AIX 7.2 TL5 SP06 and 7.3 TL1 SP02. | Added iFix for VIOS 3.1.4.21. =============================================================================== *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.