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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2023.6811 IBM WebSphere Application Server Liberty is vulnerable to a denial of service (CVE-2023-44487) 16 November 2023 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: WebSphere Application Server Publisher: IBM Operating System: AIX IBM i Linux variants Windows macOS z/OS Resolution: Patch/Upgrade CVE Names: CVE-2023-44487 Original Bulletin: https://www.ibm.com/support/pages/node/7076252 Comment: CVSS (Max): 7.5 CVE-2023-44487 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) CVSS Source: NIST Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H The following are listed in the CISA Known Exploited Vulnerabilities (KEV) Catalog: CISA KEV CVE(s): CVE-2023-44487 CISA KEV URL: https://www.cisa.gov/known-exploited-vulnerabilities-catalog - --------------------------BEGIN INCLUDED TEXT-------------------- Security Bulletin: IBM WebSphere Application Server Liberty is vulnerable to a denial of service (CVE-2023-44487) Document Information Document number : 7076252 Modified date : 15 November 2023 Product : WebSphere Application Server Component : Liberty Software version : Liberty Operating system(s): AIX IBM i Linux Windows z/OS Mac OS Security Bulletin Summary IBM WebSphere Application Server Liberty is vulnerable to a denial of service with the servlet-3.1, servlet-4.0, servlet-5.0, or servlet-6.0 feature with the HTTP/2 protocol enabled. Vulnerability Details CVEID: CVE-2023-44487 DESCRIPTION: Multiple vendors are vulnerable to a denial of service, caused by a Rapid Reset flaw in the HTTP/2 protocol. By sending numerous HTTP/2 requests and RST_STREAM frames over multiple streams, a remote attacker could consume excessive server side resources. CVSS Base score: 7.5 CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/ 268044 for the current score. CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) Affected Products and Versions +----------------------------------------+------------------+ |Affected Product(s) |Version(s) | +----------------------------------------+------------------+ |IBM WebSphere Application Server Liberty|18.0.0.2-23.0.0.11| +----------------------------------------+------------------+ Remediation/Fixes IBM strongly recommends addressing the vulnerability now by applying a currently available interim fix or fix pack that contains the APAR PH57878 . To determine if a feature is enabled for IBM WebSphere Application Server Liberty, refer to How to determine if Liberty is using a specific feature . To determine if the HTTP/2 protocol is enabled with Liberty Servlet features see HTTP/2 Support for Liberty. For IBM WebSphere Application Server Liberty 18.0.0.2 - 23.0.0.11 using the servlet-3.1, servlet-4.0, servlet-5.0, or servlet-6.0 feature(s) with the HTTP/ 2 protocol enabled: . Upgrade to minimal fix pack levels as required by interim fix and then apply Interim Fix PH57878 - --OR-- . Apply Liberty Fix Pack 23.0.0.12 or later (targeted availability 4Q2023). Additional interim fixes may be available and linked off the interim fix download page. Workarounds and Mitigations None To determine if a feature is enabled for IBM WebSphere Application Server Liberty, refer to How to determine if Liberty is using a specific feature . Acknowledgement Change History 15 Nov 2023: Initial Publication *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. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions. - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. 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On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: https://auscert.org.au/gpg-key/ iQIVAwUBZVWreckNZI30y1K9AQh9PxAArbDWBoFbFVHMXZJv8lDVRarNbEXI8NA2 GxF/yiDs5obz/tU+miMSTZ/gSGsOlOQ4HoAYiOwGBo8/CPp9n6vFXJm7S6Ce8xBz vEMjVjJSnFTT+JtPqf+rCJKsTWZb2RRjbXpyWJx2NedSDNbjXmOKck/Xhoh6QhgU oU8IC6IXdWj5ZaB+QX/famd7YPZ4nrWvy4+iG2nh0ZOMINur0EbpBM4FcqFTzlz0 4AEfLqAadN0O9+w8a9cIvqWvIMggJxfB81RGKvHrrt8RHzoHLYlrYVr5vUaWSL0H fNzn1/9tD7YlSFX5Tk3H79ybxTWGi0grKUroOkJicoicRmFCWt4ZHPeosoSnYHck 2n1YLIm42aFoidkRSYoNaujBmKokkjT1GxcxbxPsG2WJYeYjLdg39slpPgFnB8fI EBzuC7eEqzYK+eo9EUXIC6Yo2b8yX49TZjznvf6yP/ICipaPSCRBJ2tRapzXTYZ8 XTzIsOPVVCuMEyF+qzx/mQfnZTn7qkFvx5HOBatySKOQhyhN0/rsTfw2w4jcLwUC TzKZo00JHPqF5PLk8QHFRn+/W/+DcM49kYD9CwWD4yZv9F50NzNbNDatK4oHU/tE L7boa+D/a6tDLIDHPUdU7kpVXKG+uaNBj2Ympd35AdXVlmA8rMUrEbG2u2UY/bit ThjV1jCWz/c= =50i0 -----END PGP SIGNATURE-----