1. Ubuntu Security Notices
  2. USN-3823-1

USN-3823-1: Linux kernel vulnerabilities

Publication date

15 November 2018

Overview

Several security issues were mitigated in the Linux kernel.

Releases

Packages

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)

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

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.

Learn more about how to get the fixes.

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.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
12.04 precise linux-image-3.2.0-137-highbank –  3.2.0-137.183
linux-image-powerpc –  3.2.0.137.152
linux-image-powerpc-smp –  3.2.0.137.152
linux-image-generic –  3.2.0.137.152
linux-image-3.2.0-137-generic-pae –  3.2.0-137.183
linux-image-highbank –  3.2.0.137.152
linux-image-virtual –  3.2.0.137.152
linux-image-3.2.0-137-omap –  3.2.0-137.183
linux-image-3.2.0-137-powerpc64-smp –  3.2.0-137.183
linux-image-generic-pae –  3.2.0.137.152
linux-image-3.2.0-137-generic –  3.2.0-137.183
linux-image-3.2.0-137-virtual –  3.2.0-137.183
linux-image-omap –  3.2.0.137.152
linux-image-3.2.0-137-powerpc-smp –  3.2.0-137.183
linux-image-powerpc64-smp –  3.2.0.137.152

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References

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