IBM SECURITY ADVISORY First Issued: Tue Nov 16 13:38:36 CST 2021 |Updated: Fri Mar 17 15:26:09 CDT 2023 |Update: Corrected the affected upper fileset levels for AIX 7.1 TL5 | to show that SP11 is affected. Added iFix for 7.1 TL5 SP11. The most recent version of this document is available here: http://aix.software.ibm.com/aix/efixes/security/libc_advisory2.asc https://aix.software.ibm.com/aix/efixes/security/libc_advisory2.asc ftp://aix.software.ibm.com/aix/efixes/security/libc_advisory2.asc Security Bulletin: Vulnerability in libc affects AIX (CVE-2021-29860) =============================================================================== SUMMARY: There is a vulnerability in the libc.a library that affects AIX. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2021-29860 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-29860 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-29860 DESCRIPTION: IBM AIX could allow a non-privileged local user to exploit a vulnerability in the libc.a library to expose sensitive information. CVSS Base Score: 6.2 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/206084 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N) 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.rte.libc 7.1.5.0 7.1.5.39 key_w_fs bos.rte.libc 7.2.3.0 7.2.3.20 key_w_fs bos.rte.libc 7.2.4.0 7.2.4.3 key_w_fs bos.rte.libc 7.2.5.0 7.2.5.2 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.libc REMEDIATION: A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR Availability SP KEY ----------------------------------------------------- | 7.1.5 IJ35673 ** SP12 key_w_apar 7.2.4 IJ35675 ** SP05 key_w_apar 7.2.5 IJ32736 ** SP03-2135 key_w_apar VIOS Level APAR Availability SP KEY ---------------------------------------------------- 3.1.0 IJ35674 ** N/A key_w_apar 3.1.1 IJ35675 ** 3.1.1.50 key_w_apar 3.1.2 IJ32714 ** 3.1.2.30 key_w_apar Subscribe to the APARs here: http://www.ibm.com/support/pages/apar/IJ35673 http://www.ibm.com/support/pages/apar/IJ35674 http://www.ibm.com/support/pages/apar/IJ35675 http://www.ibm.com/support/pages/apar/IJ32714 http://www.ibm.com/support/pages/apar/IJ32736 https://www.ibm.com/support/pages/apar/IJ35673 https://www.ibm.com/support/pages/apar/IJ35674 https://www.ibm.com/support/pages/apar/IJ35675 https://www.ibm.com/support/pages/apar/IJ32714 https://www.ibm.com/support/pages/apar/IJ32736 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/libc_fix2.tar http://aix.software.ibm.com/aix/efixes/security/libc_fix2.tar https://aix.software.ibm.com/aix/efixes/security/libc_fix2.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 IJ33560m7b.211112.epkg.Z key_w_fix 7.1.5.8 IJ33560m8b.211112.epkg.Z key_w_fix 7.1.5.9 IJ35673s9a.211115.epkg.Z key_w_fix | 7.1.5.10 IJ35673sAa.221206.epkg.Z key_w_fix | 7.1.5.11 IJ35673sBa.230314.epkg.Z key_w_fix 7.2.4.2 IJ34512m2a.211112.epkg.Z key_w_fix 7.2.4.3 IJ34512m3a.211112.epkg.Z key_w_fix 7.2.4.4 IJ34512m4a.211112.epkg.Z key_w_fix 7.2.5.1 IJ34081m1a.211112.epkg.Z key_w_fix 7.2.5.2 IJ34081m2b.211112.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 ----------------------------------------------- 3.1.0.40 IJ35681m5a.211112.epkg.Z key_w_fix 3.1.0.50 IJ35681m6a.211112.epkg.Z key_w_fix 3.1.0.60 IJ35681m7a.211112.epkg.Z key_w_fix 3.1.1.21 IJ34512m2a.211112.epkg.Z key_w_fix 3.1.1.25 IJ34512m2a.211112.epkg.Z key_w_fix 3.1.1.30 IJ34512m3a.211112.epkg.Z key_w_fix 3.1.1.40 IJ34512m4a.211112.epkg.Z key_w_fix 3.1.2.10 IJ34081m1a.211112.epkg.Z key_w_fix 3.1.2.21 IJ34081m2b.211112.epkg.Z key_w_fix For AIX 7.1, the provided fixes include and replace the following previously published vulnerabiilty fixes: 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 For AIX 7.2 and VIOS, the provided fixes should not conflict and can be installed in addition to any previously published vulnerability fixes. To extract the fixes from the tar file: tar xvf libc_fix2.tar cd libc_fix2 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 ----------------------------------------------------------------------------------------------------- a997f0597986a2c77789aac9fb256a3e0d513311ef7bd7c7dbdd67ca1ba56ae7 IJ33560m7b.211112.epkg.Z key_w_csum 7490cde41556847c89f96b6f079e2287e29ea4e5100db2fd96fe32f0128c24f7 IJ33560m8b.211112.epkg.Z key_w_csum eb592775a18c77a0751678905ac881401aad886471b1c627abceda3bbdec5536 IJ34081m1a.211112.epkg.Z key_w_csum b8f192c3a39508d11142b99ddd881fa73d929d90a8965a952356945d4b1ba31a IJ34081m2b.211112.epkg.Z key_w_csum b59b364cc0238ecd58a9b2d0b7dd853e58f29fca217a629569c10fe113dc3547 IJ34512m2a.211112.epkg.Z key_w_csum d86f61f1f4d560c16681e98fd07def998e9189a55e59cb2449b5cb38b2d9a66e IJ34512m3a.211112.epkg.Z key_w_csum 4839f55dd72f1a88417e899570104c48154501f2f0d22d03bf2655f29400c8ad IJ34512m4a.211112.epkg.Z key_w_csum b7de872284deb63d440146d39bd9bb77afb6b61f38d63d99c8ee08f5333685c8 IJ35673s9a.211115.epkg.Z key_w_csum | 31bb35d16b5b0600f54648f1938e690751bf190bd80b9ef8745ebfb44e97f925 IJ35673sAa.221206.epkg.Z key_w_csum | 78fa436ea8df1c6271eef3d2c3bca34f7385b2422115540e583e3007cc1107be IJ35673sBa.230314.epkg.Z key_w_csum 846d36d37de4c925a9090de3720eacd53001b3526411e14cdc972b32d43b9b3f IJ35681m5a.211112.epkg.Z key_w_csum 240a051b6fb954a3db28a5269324ad745f9ea86615724aba76615b5ae2112108 IJ35681m6a.211112.epkg.Z key_w_csum b820d632ea6f601f2c748342f9c3f6719b3839aa916b531f3f0a3ea5be424f24 IJ35681m7a.211112.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/libc_advisory2.asc.sig https://aix.software.ibm.com/aix/efixes/security/libc_advisory2.asc.sig ftp://aix.software.ibm.com/aix/efixes/security/libc_advisory2.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 libc affects AIX (CVE-2021-29860) https://www.ibm.com/support/pages/node/6516774 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Tue Nov 16 13:38:36 CST 2021 | Updated: Tue Dec 6 14:22:12 CST 2022 | Update: Corrected the affected upper fileset levels for AIX 7.1 TL5 | to show that SP10 is affected. Added iFix for 7.1 TL5 SP10. | Updated: Fri Mar 17 15:26:09 CDT 2023 | Update: Corrected the affected upper fileset levels for AIX 7.1 TL5 | to show that SP11 is affected. Added iFix for 7.1 TL5 SP11. =============================================================================== *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.