IBM SECURITY ADVISORY First Issued: Thu Dec 22 10:28:36 CST 2022 |Updated: Wed May 17 11:19:24 CDT 2023 |Update: Corrected the affected fileset levels for AIX 7.2 TL5 and removed | bos.net.tcp.bind 7.2.5.200. The most recent version of this document is available here: https://aix.software.ibm.com/aix/efixes/security/bind_advisory22.asc Security Bulletin: AIX is vulnerable to denial of service due to ISC BIND (CVE-2022-38178, CVE-2022-3080, CVE-2022-38177, CVE-2022-2795) =============================================================================== SUMMARY: A vulnerability in ISC BIND could allow a remote attacker to cause a denial of service (CVE-2022-38178, CVE-2022-3080, CVE-2022-38177, CVE-2022-2795). AIX uses ISC BIND as part of its DNS functions. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2022-38178 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-38178 DESCRIPTION: ISC BIND is vulnerable to a denial of service, caused by a memory leak in the DNSSEC verification code for the EdDSA algorithm. By spoofing the target resolver with responses that have a malformed EdDSA signature, a remote attacker could exploit this vulnerability to cause named to crash. CVSS Base Score: 7.5 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/236706 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) CVEID: CVE-2022-3080 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-3080 DESCRIPTION: ISC BIND is vulnerable to a denial of service, caused by an error when stale cache and stale answers are enabled, option stale-answer-client-timeout is set to 0 and there is a stale CNAME in the cache for an incoming query. By sending a specially-crafted request, a remote attacker could exploit this vulnerability to cause named to crash. CVSS Base Score: 7.5 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/236704 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) CVEID: CVE-2022-38177 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-38177 DESCRIPTION: ISC BIND is vulnerable to a denial of service, caused by a small memory leak in the DNSSEC verification code for the ECDSA algorithm. By spoofing the target resolver with responses that have a malformed ECDSA signature, a remote attacker could exploit this vulnerability to cause named to crash. CVSS Base Score: 7.5 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/236705 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) CVEID: CVE-2022-2795 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-2795 DESCRIPTION: ISC BIND is vulnerable to a denial of service, caused by a flaw in resolver code. By flooding the target resolver with queries, a remote attacker could exploit this vulnerability to severely degrade the resolver's performance, effectively denying legitimate clients access to the DNS resolution service. CVSS Base Score: 5.3 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/236701 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L) AFFECTED PRODUCTS AND VERSIONS: AIX 7.1, 7.2, 7.3 VIOS 3.1 The following fileset levels are vulnerable: key_fileset = aix Fileset Lower Level Upper Level KEY ---------------------------------------------------------- bos.net.tcp.server 7.1.5.0 7.1.5.35 key_w_fs | bos.net.tcp.client 7.1.5.0 7.1.5.42 key_w_fs | bos.net.tcp.bind_utils 7.2.5.0 7.2.5.4 key_w_fs | bos.net.tcp.bind_utils 7.2.5.100 7.2.5.102 key_w_fs | bos.net.tcp.bind_utils 7.2.5.200 7.2.5.200 key_w_fs | bos.net.tcp.bind_utils 7.3.0.0 7.3.0.2 key_w_fs bind.rte 7.1.916.0 7.1.916.2600 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.net.tcp.server REMEDIATION: A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR Availability SP KEY ----------------------------------------------------- | 7.1.5 IJ44422 ** SP12 key_w_apar 7.2.5 IJ44425 ** SP06 key_w_apar | 7.3.0 IJ44427 ** SP04 key_w_apar 7.3.1 IJ44426 ** SP02 key_w_apar VIOS Level APAR Availability SP KEY ----------------------------------------------------- | 3.1.2 IJ44423 ** 3.1.2.60 key_w_apar | 3.1.3 IJ44424 ** 3.1.3.40 key_w_apar 3.1.4 IJ44425 ** 3.1.4.20 key_w_apar Subscribe to the APARs here: https://www.ibm.com/support/pages/apar/IJ44422 https://www.ibm.com/support/pages/apar/IJ44424 https://www.ibm.com/support/pages/apar/IJ44423 https://www.ibm.com/support/pages/apar/IJ44425 https://www.ibm.com/support/pages/apar/IJ44426 https://www.ibm.com/support/pages/apar/IJ44427 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 BIND security bulletins with respect to SP and TL. The AIX and VIOS fixes can be downloaded via https from: https://aix.software.ibm.com/aix/efixes/security/bind_fix22.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 ---------------------------------------------- 7.1.5.8 IJ44422mAa.221220.epkg.Z key_w_fix 7.1.5.9 IJ44422mAa.221220.epkg.Z key_w_fix 7.1.5.10 IJ44422mAa.221220.epkg.Z key_w_fix | 7.1.5.11 IJ44422sBa.230317.epkg.Z key_w_fix | 7.2.5.3 IJ44425m4b.230217.epkg.Z key_w_fix | 7.2.5.4 IJ44425m4b.230217.epkg.Z key_w_fix | 7.2.5.5 IJ44425s5b.230214.epkg.Z key_w_fix 7.3.0.1 IJ44427m2a.221220.epkg.Z key_w_fix 7.3.0.2 IJ44427m2a.221220.epkg.Z key_w_fix | 7.3.0.3 IJ44427s3a.230317.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 IJ44423m2b.230217.epkg.Z key_w_fix | 3.1.2.30 IJ44423m2b.230217.epkg.Z key_w_fix | 3.1.2.40 IJ44423m2b.230217.epkg.Z key_w_fix | 3.1.2.50 IJ44423s5a.230404.epkg.Z key_w_fix | 3.1.3.10 IJ44425m4b.230217.epkg.Z key_w_fix | 3.1.3.14 IJ44425m4b.230217.epkg.Z key_w_fix | 3.1.3.21 IJ44425m4b.230217.epkg.Z key_w_fix | 3.1.3.30 IJ44424s3a.230404.epkg.Z key_w_fix | 3.1.4.10 IJ44425s5b.230214.epkg.Z key_w_fix For bind.rte on 7.3 TL1 and if installed on 7.2 TL5: AIX Level Interim Fix (*.Z) KEY ---------------------------------------------- 7.2.5 IJ44426s2.221130.epkg.Z key_w_fix 7.3.1 IJ44426s2.221130.epkg.Z key_w_fix To extract the fixes from the tar file: tar xvf bind_fix22.tar cd bind_fix22 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 ----------------------------------------------------------------------------------------------------- d4c4f5597a935695bafffa5a9f31a17c694f003c0a01a3dc2d9d0ccfe06153a9 IJ44422mAa.221220.epkg.Z key_w_csum | dc937745acdc4d7e3eec7ebd256f18bfce782ad1458eb439bf05e61367b2598d IJ44422sBa.230317.epkg.Z key_w_csum | 70f95b035123da0b39350c88c57040725ee1f1421931be5354b5e4a56e446f96 IJ44423m2b.230217.epkg.Z key_w_csum | 4dbd611880ec795916fdd80ee67c971d19d4887c3027a947cee787f44574b319 IJ44423s5a.230404.epkg.Z key_w_csum | 50436dbd5b5cfa37efa361420af1638f1769a50011ee61e739990bb457f43952 IJ44424s3a.230404.epkg.Z key_w_csum | 46f8fad10cb6bc6f611f9981f41992855702ec11725bb05379db77593459b7b3 IJ44425m4b.230217.epkg.Z key_w_csum | 2245c6270194dddf66b5ba6dd7624921062910d07e6c80a61fdf82270489a3b3 IJ44425s5b.230214.epkg.Z key_w_csum 95bbb3346e950c4f920b30f016f2f6c60dbf87e27b9ae396a4c25dbd0e400573 IJ44426s2.221130.epkg.Z key_w_csum 648bd3bbedd6396f917de3deef892b04e3224c5ab40f9667ada4ef464698ccfb IJ44427m2a.221220.epkg.Z key_w_csum | 64687c4d69d5ab4cc2c2bbe72f884bdc5dd0cf65a6d7cebf2f9f18cb877c973b IJ44427s3a.230317.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/bind_advisory22.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": https://www.ibm.com/support/mynotifications Contact IBM Support for questions related to this announcement: 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 denial of service due to ISC BIND (CVE-2022-38178, CVE-2022-3080, CVE-2022-38177, CVE-2022-2795) https://www.ibm.com/support/pages/node/6851445 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Thu Dec 22 10:28:36 CST 2022 | Updated: Wed Dec 28 16:08:48 CST 2022 | Update: Added fileset information for AIX 7.2 TL5 SP5. | Updated: Wed Feb 22 09:05:51 CST 2023 | Update: New iFixes provided for AIX 7.2 TL5 and VIOS 3.1. | The new iFixes are intended to replace the original iFixes due to a | technical issue that could cause named to core dump. | Updated: Wed Apr 5 11:27:13 CDT 2023 | Update: Corrected the affected upper fileset levels for AIX to show | that AIX 7.1 TL5 SP11 and 7.3 TL0 SP03 are 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 7.1 TL5 SP11 and 7.3 TL0 SP03. | Added iFixes for VIOS 3.1.2.50 and 3.1.3.30. | Updated: Wed May 17 11:19:24 CDT 2023 | Update: Corrected the affected fileset levels for AIX 7.2 TL5 and removed | bos.net.tcp.bind 7.2.5.200. =============================================================================== *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.