IBM SECURITY ADVISORY First Issued: Wed Feb 23 13:03:11 CST 2022 The most recent version of this document is available here: http://aix.software.ibm.com/aix/efixes/security/kernel_advisory3.asc https://aix.software.ibm.com/aix/efixes/security/kernel_advisory3.asc ftp://aix.software.ibm.com/aix/efixes/security/kernel_advisory3.asc Security Bulletin: Vulnerabilities in the AIX kernel (CVE-2021-38994, CVE-2021-38995) =============================================================================== SUMMARY: There are multiple vulnerabilities in the AIX kernel. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2021-38994 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38994 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38994 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/213072 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) CVEID: CVE-2021-38995 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38995 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38995 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/213073 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 VIOS 3.1 The vulnerabilities in the following filesets are being addressed: key_fileset = aix Fileset Lower Level Upper Level KEY --------------------------------------------------------- bos.mp64 7.1.5.0 7.1.5.45 key_w_fs bos.mp64 7.2.4.0 7.2.4.9 key_w_fs bos.mp64 7.2.5.0 7.2.5.3 key_w_fs bos.mp64 7.2.5.100 7.2.5.103 key_w_fs bos.mp64 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.mp64 REMEDIATION: A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR Availability SP KEY ----------------------------------------------------- 7.1.5 IJ37452 ** SP10 key_w_apar 7.2.4 IJ37501 ** SP06 key_w_apar 7.2.5 IJ37012 ** SP04 key_w_apar 7.3.0 IJ37001 ** SP02 key_w_apar VIOS Level APAR Availability SP KEY ---------------------------------------------------- 3.1.1 IJ37501 ** 3.1.1.60 key_w_apar 3.1.2 IJ37776 ** 3.1.2.40 key_w_apar 3.1.3 IJ37012 ** 3.1.3.20 key_w_apar Subscribe to the APARs here: http://www.ibm.com/support/pages/apar/IJ37001 http://www.ibm.com/support/pages/apar/IJ37012 http://www.ibm.com/support/pages/apar/IJ37452 http://www.ibm.com/support/pages/apar/IJ37501 http://www.ibm.com/support/pages/apar/IJ37776 https://www.ibm.com/support/pages/apar/IJ37001 https://www.ibm.com/support/pages/apar/IJ37012 https://www.ibm.com/support/pages/apar/IJ37452 https://www.ibm.com/support/pages/apar/IJ37501 https://www.ibm.com/support/pages/apar/IJ37776 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 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/kernel_fix3.tar http://aix.software.ibm.com/aix/efixes/security/kernel_fix3.tar https://aix.software.ibm.com/aix/efixes/security/kernel_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 ---------------------------------------------- 7.1.5.7 IJ37452m7a.220215.epkg.Z key_w_fix 7.1.5.8 IJ37452m8a.220215.epkg.Z key_w_fix 7.1.5.9 IJ37452s9a.220215.epkg.Z key_w_fix 7.1.5.9 IJ37452s9b.220215.epkg.Z key_w_fix 7.2.4.3 IJ37501m3a.220215.epkg.Z key_w_fix 7.2.4.4 IJ37501m4a.220215.epkg.Z key_w_fix 7.2.4.5 IJ37501m5a.220215.epkg.Z key_w_fix 7.2.5.1 IJ37776m1a.220215.epkg.Z key_w_fix 7.2.5.2 IJ37776m2a.220215.epkg.Z key_w_fix 7.2.5.3 IJ37012m3a.220215.epkg.Z key_w_fix 7.2.5.3 IJ37012m3b.220215.epkg.Z key_w_fix 7.3.0.1 IJ37001m1a.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. NOTE: Multiple iFixes are provided for AIX 7100-05-09 and 7200-05-03. IJ37452s9a is for AIX 7100-05-09 with bos.mp64 fileset level 7.1.5.45. IJ37452s9b is for AIX 7100-05-09 with bos.mp64 fileset level 7.1.5.44. IJ37012m3a is for AIX 7200-05-03 with bos.mp64 fileset level 7.2.5.103. IJ37012m3b is for AIX 7200-05-03 with bos.mp64 fileset level 7.2.5.101. 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 IJ37501m3a.220215.epkg.Z key_w_fix 3.1.1.40 IJ37501m4a.220215.epkg.Z key_w_fix 3.1.1.50 IJ37501m5a.220215.epkg.Z key_w_fix 3.1.2.10 IJ37776m1a.220215.epkg.Z key_w_fix 3.1.2.21 IJ37776m2a.220215.epkg.Z key_w_fix 3.1.3.10 IJ37012m3b.220215.epkg.Z key_w_fix 3.1.3.14 IJ37012m3a.220215.epkg.Z key_w_fix The fixes are cumulative and address previously issued AIX/VIOS kernel security bulletins with respect to SP and TL, which includes: https://aix.software.ibm.com/aix/efixes/security/kernel_advisory2.asc https://www.ibm.com/support/pages/node/6483875 https://aix.software.ibm.com/aix/efixes/security/trace_advisory.asc https://www.ibm.com/support/pages/node/6464369 https://aix.software.ibm.com/aix/efixes/security/gencore_advisory.asc https://www.ibm.com/support/pages/node/6406022 https://aix.software.ibm.com/aix/efixes/security/power9_advisory.asc https://www.ibm.com/support/pages/node/6370729 The fixes for 7.1 TL5 SP7 and SP8 include the following. The fix for 7.1 TL5 SP9 should be installed alongside the following: https://aix.software.ibm.com/aix/efixes/security/libc_advisory2.asc https://www.ibm.com/support/pages/node/6516774 To extract the fixes from the tar file: tar xvf kernel_fix3.tar cd kernel_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 ----------------------------------------------------------------------------------------------------- 10e4ef561cfb0e44a698948eaa3f157c1fbdd22dc6b9095898f813e4e306fa55 IJ37001m1a.220215.epkg.Z key_w_csum 70e53abb9b1b60222a215b04373a79c315d003d5f174f9e1b2fa521bd3201c35 IJ37012m3a.220215.epkg.Z key_w_csum b575eff5b745fabc369477cec9408e35bfac445d77835ed4df4836ca56fb7cf0 IJ37012m3b.220215.epkg.Z key_w_csum 7c3c4f2aaa7a3624066785211735decfe33bef38c01dff62c3c075f0c4ba535a IJ37452m7a.220215.epkg.Z key_w_csum 328b6d14775423691f5c3b746367e9fdbd24b71230195b93124e2066be499dc4 IJ37452m8a.220215.epkg.Z key_w_csum 6ffa2ad6d1dff2252b4cc5f6e7dfc1a83d15dedc44e0d35f69bfd7b01aab39b8 IJ37452s9a.220215.epkg.Z key_w_csum e4c7fffdc340a122e42e3a1ce73a6f20ccf0d045dcd4958bc82b69b08add18d8 IJ37452s9b.220215.epkg.Z key_w_csum ba1c1b1fbe6c1f6a68b6dd48d0f5e61221751d288e8bb141c5e4c2b806322044 IJ37501m3a.220215.epkg.Z key_w_csum f0dc84ce2145a301b8e7ddbc0e6335bc93fe6468fafb67dd3b67bf73b535c5df IJ37501m4a.220215.epkg.Z key_w_csum 467d4747459d37489b2199d57836de3d79a3837b95c2aa29dc35f43fe33bd0ed IJ37501m5a.220215.epkg.Z key_w_csum 9acb84e45fa3aa0b8d36e9f63d29dcc0e335c0d55351a2a5b8433bd57075dc01 IJ37776m1a.220215.epkg.Z key_w_csum 30e03d25a0657290afb9c04ac1b5b06fd87a8a776dfe037b2d5dd9b92e16c7cd IJ37776m2a.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/kernel_advisory3.asc.sig https://aix.software.ibm.com/aix/efixes/security/kernel_advisory3.asc.sig ftp://aix.software.ibm.com/aix/efixes/security/kernel_advisory3.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: Vulnerabilities in the AIX kernel (CVE-2021-38994, CVE-2021-38995) https://www.ibm.com/support/pages/node/6558948 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Wed Feb 23 13:03:11 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.