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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2021.3017 USN-5062-1: Linux kernel vulnerability 8 September 2021 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: linux kernel Publisher: Ubuntu Operating System: Ubuntu UNIX variants (UNIX, Linux, OSX) Impact/Access: Execute Arbitrary Code/Commands -- Existing Account Increased Privileges -- Existing Account Denial of Service -- Existing Account Reduced Security -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2021-3653 Original Bulletin: https://ubuntu.com/security/notices/USN-5062-1 Comment: This advisory references vulnerabilities in the Linux kernel that also affect distributions other than Ubuntu. It is recommended that administrators running Linux check for an updated version of the kernel for their system. - --------------------------BEGIN INCLUDED TEXT-------------------- USN-5062-1: Linux kernel vulnerability 08 September 2021 The system could be made to crash or run programs as an administrator. Releases o Ubuntu 16.04 ESM o Ubuntu 14.04 ESM Packages o linux - Linux kernel o linux-aws - Linux kernel for Amazon Web Services (AWS) systems o linux-kvm - Linux kernel for cloud environments o linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty Details Maxim Levitsky discovered that the KVM hypervisor implementation for AMD processors in the Linux kernel did not properly prevent a guest VM from enabling AVIC in nested guest VMs. An attacker in a guest VM could use this to write to portions of the host's physical memory. Update instructions The problem can be corrected by updating your system to the following package versions: Ubuntu 16.04 o linux-image-4.4.0-1097-kvm - 4.4.0-1097.106 Available with UA Infra or UA Desktop o linux-image-4.4.0-1132-aws - 4.4.0-1132.146 Available with UA Infra or UA Desktop o linux-image-4.4.0-214-generic - 4.4.0-214.246 Available with UA Infra or UA Desktop o linux-image-4.4.0-214-lowlatency - 4.4.0-214.246 Available with UA Infra or UA Desktop o linux-image-aws - 4.4.0.1132.137 Available with UA Infra or UA Desktop o linux-image-generic - 4.4.0.214.221 Available with UA Infra or UA Desktop o linux-image-kvm - 4.4.0.1097.95 Available with UA Infra or UA Desktop o linux-image-lowlatency - 4.4.0.214.221 Available with UA Infra or UA Desktop o linux-image-virtual - 4.4.0.214.221 Available with UA Infra or UA Desktop Ubuntu 14.04 o linux-image-4.4.0-1096-aws - 4.4.0-1096.101 Available with UA Infra or UA Desktop o linux-image-4.4.0-214-generic - 4.4.0-214.246~14.04.1 Available with UA Infra or UA Desktop o linux-image-4.4.0-214-lowlatency - 4.4.0-214.246~14.04.1 Available with UA Infra or UA Desktop o linux-image-aws - 4.4.0.1096.94 Available with UA Infra or UA Desktop o linux-image-generic-lts-xenial - 4.4.0.214.187 Available with UA Infra or UA Desktop o linux-image-lowlatency-lts-xenial - 4.4.0.214.187 Available with UA Infra or UA Desktop o linux-image-virtual-lts-xenial - 4.4.0.214.187 Available with UA Infra or UA Desktop After a standard system update you need to reboot your computer to make all the necessary changes. ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well. References o CVE-2021-3653 - --------------------------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://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBYTgtW+NLKJtyKPYoAQgTrA/+OHMhkXCaUQwCY0Zov/bOffgTuJ0M19gX S4z6ALR06PCEu0oBcCZmgu0imaIkrU+MARrgPidSpzOfSUw9FNsugYIyfe7XcMZr x/NxJaL3ICkUhYM3/+zOpQr6w4yUeVBsu+in/2JgjhwXBZwXInndjv+J10LXSaW0 CiTe0RCjk/FQgN6q0vR/pQosEuXLEgIN1kbooNF8I9p3O3/f2tv5Ap62Pa++03Iq nVMNnsJuajBSMcrFFRgFFYdKEKAx4q1h0TFfpmaBDSU2lIeMDhXkFdjZbiqu/zYU 5eoKcMnBDZX3k+kot3APvTNjcjXTUwdZ08SpamzVnM6umeOycs3clxDMyjvsC3c7 74MkEl7j5/DBySDFwVTijhIcTUNqEcSIt8mnYCi/Yk2iCRSzEEkBbMDl88slpIAS HMHmUjsln+Bn2qC+nM6kitIhUpoZcap8fxjG9THU5h37x5M4or/Qk9bDP4Srj6HH +vAXwHqFptqCokioXmTu3k5Q5QljRvCgseu45lbQN3nCSRbbgUGicxe0WrxyM0H+ YONektLhFJbRhpIGW53C4PW4WA3pYL8mHUm/vgaedKiMnQ6h5Xi/9UTi+hJlxDcj gpsCywZDGdfbiQc5OYnmJ2gPxnqPp9nbzfjQ9v8Gxr4cvWgmE61CO2+41to06gv2 UQyCH6aRWcI= =iZrC -----END PGP SIGNATURE-----