========================================================================== Ubuntu Security Notice USN-3823-1 November 15, 2018 linux vulnerabilities ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 12.04 ESM Summary: Several security issues were mitigated in the Linux kernel. Software Description: - linux: Linux kernel Details: It was discovered that memory present in the L1 data cache of an Intel CPU core may be exposed to a malicious process that is executing on the CPU core. This vulnerability is also known as L1 Terminal Fault (L1TF). A local attacker in a guest virtual machine could use this to expose sensitive information (memory from other guests or the host OS). (CVE-2018-3646) It was discovered that memory present in the L1 data cache of an Intel CPU core may be exposed to a malicious process that is executing on the CPU core. This vulnerability is also known as L1 Terminal Fault (L1TF). A local attacker could use this to expose sensitive information (memory from the kernel or other processes). (CVE-2018-3620) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 12.04 ESM: linux-image-3.2.0-137-generic 3.2.0-137.183 linux-image-3.2.0-137-generic-pae 3.2.0-137.183 linux-image-3.2.0-137-highbank 3.2.0-137.183 linux-image-3.2.0-137-omap 3.2.0-137.183 linux-image-3.2.0-137-powerpc-smp 3.2.0-137.183 linux-image-3.2.0-137-powerpc64-smp 3.2.0-137.183 linux-image-3.2.0-137-virtual 3.2.0-137.183 linux-image-generic 3.2.0.137.152 linux-image-generic-pae 3.2.0.137.152 linux-image-highbank 3.2.0.137.152 linux-image-omap 3.2.0.137.152 linux-image-powerpc 3.2.0.137.152 linux-image-powerpc-smp 3.2.0.137.152 linux-image-powerpc64-smp 3.2.0.137.152 linux-image-virtual 3.2.0.137.152 Please note that the recommended mitigation for CVE-2018-3646 involves updating processor microcode in addition to updating the kernel; however, the kernel includes a fallback for processors that have not received microcode updates. 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: https://usn.ubuntu.com/usn/usn-3823-1 CVE-2018-3620, CVE-2018-3646, https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/L1TF