IBM SECURITY ADVISORY First Issued: Mon Oct 13 08:46:48 CDT 2025 The most recent version of this document is available here: https://aix.software.ibm.com/aix/efixes/security/xorg_advisory4.asc Security Bulletin: AIX is vulnerable to a denial of service (CVE-2025-49175, CVE-2025-49178) and an integer overflow (CVE-2025-49176, CVE-2025-49179) =============================================================================== SUMMARY: Vulnerabilities in Xorg X Server could cause a denial of service (CVE-2025-49175, CVE-2025-49178) or an integer overflow (CVE-2025-49176, CVE-2025-49179). =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2025-49175 https://www.cve.org/CVERecord?id=CVE-2025-49175 DESCRIPTION: A flaw was found in the X Rendering extension's handling of animated cursors. If a client provides no cursors, the server assumes at least one is present, leading to an out-of-bounds read and potential crash. CVSS Base Score: 6.1 CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H) CVEID: CVE-2025-49176 https://www.cve.org/CVERecord?id=CVE-2025-49176 DESCRIPTION: A flaw was found in the Big Requests extension. The request length is multiplied by 4 before checking against the maximum allowed size, potentially causing an integer overflow and bypassing the size check. CVSS Base Score: 7.3 CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H) CVEID: CVE-2025-49178 https://www.cve.org/CVERecord?id=CVE-2025-49178 DESCRIPTION: A flaw was found in the X server's request handling. Non-zero 'bytes to ignore' in a client's request can cause the server to skip processing another client's request, potentially leading to a denial of service. CVSS Base Score: 5.5 CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) CVEID: CVE-2025-49179 https://www.cve.org/CVERecord?id=CVE-2025-49179 DESCRIPTION: A flaw was found in the X Record extension. The RecordSanityCheckRegisterClients function does not check for an integer overflow when computing request length, which allows a client to bypass length checks. CVSS Base Score: 7.3 CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H) AFFECTED PRODUCTS AND VERSIONS: AIX 7.2, 7.3 VIOS 3.1, 4.1 The vulnerabilities in the following filesets are being addressed: key_fileset = aix Fileset Lower Level Upper Level KEY --------------------------------------------------------- X11.base.rte 7.2.5.0 7.2.5.100 key_w_fs X11.base.rte 7.3.0.0 7.3.0.0 key_w_fs X11.base.rte 7.3.3.0 7.3.3.0 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 X11.base.rte REMEDIATION: A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR Availability SP KEY ----------------------------------------------------- 7.2.5 IJ55665 ** SP11 key_w_apar 7.3.2 IJ55843 ** N/A key_w_apar 7.3.3 IJ55695 ** SP02 key_w_apar VIOS Level APAR Availability SP KEY ----------------------------------------------------- 3.1.4 IJ55665 ** N/A key_w_apar 4.1.0 IJ55843 ** N/A key_w_apar 4.1.1 IJ55695 ** 4.1.1.20 key_w_apar Subscribe to the APARs here: https://www.ibm.com/support/pages/apar/[apar number] 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 AIX and VIOS fixes can be downloaded via https from: https://aix.software.ibm.com/aix/efixes/security/xorg_fix4.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 ---------------------------------------------- 7.2.5.8 IJ55665sAa.250912.epkg.Z key_w_fix 7.2.5.9 IJ55665sAa.250912.epkg.Z key_w_fix 7.2.5.10 IJ55665sAa.250912.epkg.Z key_w_fix 7.3.1.2 IJ55843s4a.250912.epkg.Z key_w_fix 7.3.1.3 IJ55843s4a.250912.epkg.Z key_w_fix 7.3.1.4 IJ55843s4a.250912.epkg.Z key_w_fix 7.3.2.2 IJ55843s4a.250912.epkg.Z key_w_fix 7.3.2.3 IJ55843s4a.250912.epkg.Z key_w_fix 7.3.2.4 IJ55843s4a.250912.epkg.Z key_w_fix 7.3.3.0 IJ55695s1a.250912.epkg.Z key_w_fix 7.3.3.1 IJ55695s1a.250912.epkg.Z key_w_fix Please note that the above table refers to AIX TL/SP level as opposed to fileset level, i.e., 7.3.2.3 is AIX 7300-02-03. Please reference the Affected Products and Version section above for help with checking installed fileset levels. VIOS Level Interim Fix (*.Z) KEY ----------------------------------------------- 3.1.4.41 IJ55665sAa.250912.epkg.Z key_w_fix 3.1.4.50 IJ55665sAa.250912.epkg.Z key_w_fix 3.1.4.60 IJ55665sAa.250912.epkg.Z key_w_fix 4.1.0.21 IJ55843s4a.250912.epkg.Z key_w_fix 4.1.0.30 IJ55843s4a.250912.epkg.Z key_w_fix 4.1.0.40 IJ55843s4a.250912.epkg.Z key_w_fix 4.1.1.0 IJ55695s1a.250912.epkg.Z key_w_fix 4.1.1.10 IJ55695s1a.250912.epkg.Z key_w_fix To extract the fixes from the tar file: tar xvf xorg_fix4.tar cd xorg_fix4 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 ----------------------------------------------------------------------------------------------------- 0b9cb1d5d3c71ed9994bc6bf13fc0bb2d8163ebf2937086d13d40ba9219e5e74 IJ55665sAa.250912.epkg.Z key_w_csum d7685d27d25569bffe201ab84231baa6fa5da919fe5568104abf698c0ebfea94 IJ55695s1a.250912.epkg.Z key_w_csum 370b0d85f0aca635cfc1be8a4131b4f9d9a28033f52a77dafc1d66f832222cac IJ55843s4a.250912.epkg.Z key_w_csum The checksums below were generated using the "openssl dgst -sha512 [filename]" command as the following: openssl dgst -sha512 filename ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ 33d95c94e9fd5f4511cd9c4c468d4146e581a1836daf69fdbe9ab2b29e02fa33eba146b53bf528fc029a1735c1c9ad3dffff86f650aaa710e4c28e09dbd2ef34 IJ55665sAa.250912.epkg.Z key_4K_w_csum cc6605fca10f80b00c77c2d34ff7dfcbe5909260bb7c7b4feb412deebeb977d9c01bff4e8be9ef015378c085579a1abc4c3684a1954506c1a12ce94b2f8bbb2a IJ55695s1a.250912.epkg.Z key_4K_w_csum 87f800a07cec883fc56c7704f01753b865325e58546262b80d4669889feca3015a18efe46fa317f373125c7e76ad74e264f9f2e68d9ef0f40526522773c4e7b6 IJ55843s4a.250912.epkg.Z key_4K_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/xorg_advisory4.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: 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": http://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/xorg_advisory4.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: 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 a denial of service (CVE-2025-49175, CVE-2025-49178) and an integer overflow (CVE-2025-49176, CVE-2025-49179) https://www.ibm.com/support/pages/node/7247777 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Mon Oct 13 08:46:48 CDT 2025 =============================================================================== *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.