ESB-2026.3572

=========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2026.3572 USN-8172-1: kvmtool vulnerabilities 14 April 2026 =========================================================================== AUSCERT Security Bulletin Summary --------------------------------- Product: kvmtool Publisher: Ubuntu Operating System: Ubuntu Resolution: Patch/Upgrade CVE Names: CVE-2023-2861 CVE-2021-45464 Original Bulletin: https://ubuntu.com/security/notices/USN-8172-1 Comment: CVSS (Max): 8.8 CVE-2021-45464 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H) CVSS Source: Ubuntu Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H EPSS (Max): 0.1% (19th) CVE-2021-45464 2026-04-13 - --------------------------BEGIN INCLUDED TEXT-------------------- USN-8172-1: kvmtool vulnerabilities Publication date 13 April 2026 Overview Several security issues were fixed in kvmtool. Releases 22.04 LTS 20.04 LTS 18.04 LTS 16.04 LTS --------------------------------------------------------------------------------- Open side navigation Packages o kvmtool - Native Linux KVM tool Details It was discovered that kvmtool did not properly manage memory under certain circumstances. A malicious guest attacker could use this issue to cause kvmtool to crash, leading to a denial of service, or possibly execute arbitrary code on the host system. ( CVE-2021-45464 ) It was discovered that kvmtool incorrectly handled the 9p passthrough file system. A malicious guest attacker could possibly use this issue to open special files, escape the exported 9p tree, and execute arbitrary code on the host system. ( CVE-2023-2861 ) Update instructions The problem can be corrected by updating your system to the following package versions: Ubuntu Package Version Release 22.04 kvmtool - 0.20170904-1.1ubuntu0.1~esm2 Ubuntu Pro Fix available with LTS Ubuntu Pro via ESM Apps. A community fix might become publicly jammy available in the future. 20.04 kvmtool - 0.20170904-1ubuntu0.20.04.1~esm1 Ubuntu Pro Fix available LTS with Ubuntu Pro via ESM Apps. A community fix might become publicly focal available in the future. 18.04 kvmtool - 0.20170904-1ubuntu0.18.04.1~esm1 Ubuntu Pro Fix available LTS with Ubuntu Pro via ESM Apps. A community fix might become publicly bionic available in the future. 16.04 kvmtool - 0.20151104-1ubuntu0.1~esm1 Ubuntu Pro Fix available with LTS Ubuntu Pro via ESM Apps. A community fix might become publicly xenial available in the future. --------------------------------------------------------------------------------- References o CVE-2023-2861 o CVE-2021-45464 Related notices o USN-6567-1 - --------------------------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. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AUSCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://portal.auscert.org.au/bulletins/ =========================================================================== AUSCERT The University of Queensland, Brisbane QLD 4072 Australia e: auscert@auscert.org.au t: +61 (0)7 3365 4417 Allies in Cyber Security ===========================================================================