IBM SECURITY ADVISORY First Issued: Fri Mar 4 08:58:04 CST 2022 The most recent version of this document is available here: http://aix.software.ibm.com/aix/efixes/security/pmsvcs_advisory.asc https://aix.software.ibm.com/aix/efixes/security/pmsvcs_advisory.asc ftp://aix.software.ibm.com/aix/efixes/security/pmsvcs_advisory.asc Security Bulletin: Vulnerability in the AIX kernel (CVE-2021-38989) =============================================================================== SUMMARY: There is a vulnerability in the AIX pmsvcs kernel extension. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2021-38989 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38989 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38989 DESCRIPTION: IBM AIX could allow a non-privileged local user to exploit a vulnerability in the AIX kernel to cause a denial of service. CVSS Base Score: 6.2 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/212951 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) AFFECTED PRODUCTS AND VERSIONS: AIX 7.1, 7.2, 7.3 VIOS 3.1 The vulnerabilities in the following filesets are being addressed: key_fileset = aix Fileset Lower Level Upper Level KEY --------------------------------------------------------- bos.pmapi.pmsvcs 7.1.5.0 7.1.5.36 key_w_fs bos.pmapi.pmsvcs 7.2.4.0 7.2.4.4 key_w_fs bos.pmapi.pmsvcs 7.2.5.0 7.2.5.1 key_w_fs bos.pmapi.pmsvcs 7.2.5.100 7.2.5.100 key_w_fs bos.pmapi.pmsvcs 7.3.0.0 7.3.0.0 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.pmapi.pmsvcs REMEDIATION: A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR Availability SP KEY PRODUCT(S) ---------------------------------------------------------------- 7.1.5 IJ37507 ** SP10 key_w_apar base 7.2.4 IJ37503 ** SP06 key_w_apar base 7.2.5 IJ37488 ** SP04 key_w_apar base 7.3.0 IJ37411 ** SP02 key_w_apar base VIOS Level APAR Availability SP KEY PRODUCT(S) --------------------------------------------------------------- 3.1.1 IJ37503 ** 3.1.1.60 key_w_apar base 3.1.2 IJ37778 ** 3.1.2.40 key_w_apar base 3.1.3 IJ37488 ** 3.1.3.20 key_w_apar base Subscribe to the APARs here: http://www.ibm.com/support/pages/apar/IJ37411 http://www.ibm.com/support/pages/apar/IJ37488 http://www.ibm.com/support/pages/apar/IJ37503 http://www.ibm.com/support/pages/apar/IJ37507 http://www.ibm.com/support/pages/apar/IJ37778 https://www.ibm.com/support/pages/apar/IJ37411 https://www.ibm.com/support/pages/apar/IJ37488 https://www.ibm.com/support/pages/apar/IJ37503 https://www.ibm.com/support/pages/apar/IJ37507 https://www.ibm.com/support/pages/apar/IJ37778 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 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 ftp or http from: ftp://aix.software.ibm.com/aix/efixes/security/pmsvcs_fix.tar http://aix.software.ibm.com/aix/efixes/security/pmsvcs_fix.tar https://aix.software.ibm.com/aix/efixes/security/pmsvcs_fix.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 ---------------------------------------------- 7.1.5.7 IJ37507s7a.220215.epkg.Z key_w_fix 7.1.5.8 IJ37507s9a.220215.epkg.Z key_w_fix 7.1.5.9 IJ37507s9a.220215.epkg.Z key_w_fix 7.2.4.3 IJ37503s3a.220215.epkg.Z key_w_fix 7.2.4.4 IJ37503s4a.220215.epkg.Z key_w_fix 7.2.4.5 IJ37503s5a.220215.epkg.Z key_w_fix 7.2.5.1 IJ37778s1a.220215.epkg.Z key_w_fix 7.2.5.2 IJ37778s2a.220215.epkg.Z key_w_fix 7.2.5.3 IJ37488s3a.220215.epkg.Z key_w_fix 7.3.0.1 IJ37411s1a.220215.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 ----------------------------------------------- 3.1.1.30 IJ37503s3a.220215.epkg.Z key_w_fix 3.1.1.40 IJ37503s4a.220215.epkg.Z key_w_fix 3.1.1.50 IJ37503s5a.220215.epkg.Z key_w_fix 3.1.2.10 IJ37778s1a.220215.epkg.Z key_w_fix 3.1.2.21 IJ37778s2a.220215.epkg.Z key_w_fix 3.1.3.10 IJ37488s3a.220215.epkg.Z key_w_fix 3.1.3.14 IJ37488s3a.220215.epkg.Z key_w_fix To extract the fixes from the tar file: tar xvf pmsvcs_fix.tar cd pmsvcs_fix 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 ----------------------------------------------------------------------------------------------------- 29b84342adb40a9c08ade21c9dded96fc3ec32d9f70a6ece5fa57d4699c486f3 IJ37411s1a.220215.epkg.Z key_w_csum 3313f5c8b50dcd6da5d3608067e05ba1613705bb1c99f67f4e3056e59124613a IJ37488s3a.220215.epkg.Z key_w_csum 9e8df6fdb2a9d40ffc5ce7626f9773efdce5e5226bd56d73692c44a11eb2c0be IJ37503s3a.220215.epkg.Z key_w_csum d8411b04c81f4c480067a76b232c5261a6d6f0fcdab7011516b2b2f52b911f45 IJ37503s4a.220215.epkg.Z key_w_csum b29cb115e719fd68003fa9e6a75325bfbbfc75476227484025db687c9ca62e68 IJ37503s5a.220215.epkg.Z key_w_csum a75e023ab616b3fb3806cf05ffed2924acb3b172b2a696479ec2f0d1428193ef IJ37507s7a.220215.epkg.Z key_w_csum 5b9456fa0b9b46f8546b9149c04419fd6205948e412383c614953d3c37078f5c IJ37507s9a.220215.epkg.Z key_w_csum 34250efd1c456050bfd8588c85642d1b4a0b5634a9ed5091f7f2983db3a92cfc IJ37778s1a.220215.epkg.Z key_w_csum 2257aad1a356934059dbd7e583e125a0da7ce721cf161e2ae880f0f8bfa95b8a IJ37778s2a.220215.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/pmsvcs_advisory.asc.sig https://aix.software.ibm.com/aix/efixes/security/pmsvcs_advisory.asc.sig ftp://aix.software.ibm.com/aix/efixes/security/pmsvcs_advisory.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 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: 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: Vulnerability in the AIX kernel (CVE-2021-38989) https://www.ibm.com/support/pages/node/6561277 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Fri Mar 4 08:58:04 CST 2022 =============================================================================== *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.