IBM SECURITY ADVISORY First Issued: Tue Jul 30 15:25:31 CDT 2024 The most recent version of this document is available here: https://aix.software.ibm.com/aix/efixes/security/openssl_advisory42.asc Security Bulletin: AIX is vulnerable to arbitrary code execution (CVE-2024-4741) and denial of service (CVE-2024-5535, CVE-2024-4603) due to OpenSSL =============================================================================== SUMMARY: Vulnerabilities in OpenSSL could allow a remote attacker to execute arbitrary code (CVE-2024-4741) or cause a denial of service (CVE-2024-5535, CVE-2024-4603). OpenSSL is used by AIX as part of AIX's secure network communications. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2024-4741 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4741 DESCRIPTION: OpenSSL could allow a remote attacker to execute arbitrary code on the system, caused by a use-after-free flaw in the SSL_free_buffers API function . By sending a specially crafted request, an attacker could exploit this vulnerability to execute arbitrary code or cause a denial of service condition. CVSS Base Score: 8.1 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/292512 for the current score CVSS Environmental Score*: Undefined CVSS Vector:(CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H) CVEID: CVE-2024-5535 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-5535 DESCRIPTION: OpenSSL is vulnerable to a denial of service, caused by a buffer over-read flaw in the SSL_select_next_proto API function when calling with an empty supported client protocols buffer. By sending a specially crafted request, a remote attacker could exploit this vulnerability to cause a crash or memory contents to be sent to the peer. CVSS Base Score: 3.7 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/296011 for the current score CVSS Environmental Score*: Undefined CVSS Vector:(CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L) CVEID: CVE-2024-4603 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-4603 DESCRIPTION: OpenSSL is vulnerable to a denial of service, caused by improper input validation by the EVP_PKEY_param_check() or EVP_PKEY_public_check() function. By parsing a specially crafted DSA public key or DSA parameters, a remote attacker could exploit this vulnerability to cause long delays, and results in a denial of service condition. CVSS Base Score: 3.7 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/290839 for the current score CVSS Environmental Score*: Undefined CVSS Vector:(CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L) AFFECTED PRODUCTS AND VERSIONS: AIX 7.2, 7.3 VIOS 3.1, 4.1 The following fileset levels are vulnerable: key_fileset = osrcaix Fileset Lower Level Upper Level KEY ------------------------------------------------------ openssl.base 1.1.1.0 1.1.1.2400 key_w_fs openssl.base 1.1.2.0 1.1.2.2400 key_w_fs openssl.base 3.0.0.0 3.0.13.1000 key_w_fs Note: A. 0.9.8, 1.0.1 OpenSSL versions are out-of-support. Support for OpenSSL 1.0.2 version ended in December 2023. Customers are advised to upgrade to OpenSSL 1.1.1 or 3.0 version. B. CVE-2024-4603 only applies to OpenSSL 3.0 version. To find out whether the affected filesets are installed on your systems, refer to the lslpp command found in the AIX user's guide. Example: lslpp -L | grep -i openssl.base REMEDIATION: A. FIXES IBM strongly recommends addressing the vulnerability now. The fixes can be downloaded via https from: https://aix.software.ibm.com/aix/efixes/security/openssl_fix42.tar The links above are 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. Note that the tar file contains Interim fixes that are based on OpenSSL version, and AIX OpenSSL fixes are cumulative. If an OpenSSL fileset with VMRF higher than the affected level listed above is available from the web download site, then that fileset is the recommended remediation. You must be on the 'prereq for installation' level before applying the interim fix. This may require installing a new level(prereq version) first. Latest level of OpenSSL fileset is available from the web download site: https://www.ibm.com/resources/mrs/assets?source=aixbp&S_PKG=openssl AIX Level Interim Fix (*.Z) Fileset Name(prereq for installation) KEY --------------------------------------------------------------------------------------- 7.2, 7.3 1112400a.240722.epkg.Z openssl.base(1.1.1.2400) key_w_fix 7.2, 7.3 1122400a.240722.epkg.Z openssl.base(1.1.2.2400) key_w_fix 7.2, 7.3 3013sa.240722.epkg.Z openssl.base(3.0.13.1000) key_w_fix VIOS Level Interim Fix (*.Z) Fileset Name(prereq for installation) KEY --------------------------------------------------------------------------------------- 3.1 1112400a.240722.epkg.Z openssl.base(1.1.1.2400) key_w_fix 3.1 1122400a.240722.epkg.Z openssl.base(1.1.2.2400) key_w_fix 3.1, 4.1 3013sa.240722.epkg.Z openssl.base(3.0.13.1000) key_w_fix To extract the fixes from the tar file: tar xvf openssl_fix42.tar cd openssl_fix42 Verify you have retrieved the fixes intact: The checksums below were generated using the "openssl dgst -sha256 [file]" command as the following: openssl dgst -sha256 filename KEY ----------------------------------------------------------------------------------------------------- 42dbc323f64a2700e38fa4a47b71193968cea49e465577b4cda99fde219ed983 1112400a.240722.epkg.Z key_w_csum 183eca818a3324cbaaa03b5360cc08ea86f934f08dedae553072dda2739d908a 1122400a.240722.epkg.Z key_w_csum 556c3e6a2bb4dd94631933247199024202495c98500c6b65d74bb21e2d8b0c64 3013sa.240722.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 AIX Support at https://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/openssl_advisory42.asc.sig B. FIX AND INTERIM FIX INSTALLATION 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: https://www.ibm.com/support/pages/managing-interim-fixes-aix 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/ For information on how to securely verify AIX security bulletins and fixes: https://www.ibm.com/support/pages/node/6985269 To obtain the OpenSSL public key that can be used to verify the signed advisories and ifixes: Download the key from our web page: https://aix.software.ibm.com/aix/efixes/security/systems_p_os_aix_security_pubkey.txt To verify the AIX/VIOS security bulletin: Published advisory OpenSSL signature file location: https://aix.software.ibm.com/aix/efixes/security/openssl_advisory42.asc.sig openssl dgst -sha256 -verify [pubkey_file] -signature [advisory_file].sig [advisory_file] Please contact your local IBM AIX support center for any assistance. REFERENCES: Review this information as needed, no action required. Complete CVSS v3 Guide: https://www.first.org/cvss/user-guide On-line Calculator v3: https://www.first.org/cvss/calculator/3.0 RELATED INFORMATION: Security Bulletin: AIX is vulnerable to arbitrary code execution (CVE-2024-4741) and denial of service (CVE-2024-5535, CVE-2024-4603) due to OpenSSL https://www.ibm.com/support/pages/node/7162032 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Tue Jul 30 15:25:31 CDT 2024 =============================================================================== *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.