USN-3333-1: Linux kernel (HWE) vulnerability

Ubuntu Security Notice USN-3333-1

22nd June, 2017

linux-hwe vulnerability

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 16.04 LTS

Summary

The system could be made to run programs as an administrator.

Software description

  • linux-hwe - Linux hardware enablement (HWE) kernel

Details

USN-3326-1 fixed vulnerabilities in the Linux kernel for Ubuntu
16.10. This update provides the corresponding updates for the
Linux Hardware Enablement (HWE) kernel from Ubuntu 16.10 for Ubuntu
16.04 LTS.

It was discovered that the stack guard page for processes in the Linux
kernel was not sufficiently large enough to prevent overlapping with the
heap. An attacker could leverage this with another vulnerability to execute
arbitrary code and gain administrative privileges

Update instructions

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

Ubuntu 16.04 LTS:
linux-image-4.8.0-56-lowlatency 4.8.0-56.61~16.04.1
linux-image-4.8.0-56-generic 4.8.0-56.61~16.04.1
linux-image-generic-hwe-16.04 4.8.0.56.27
linux-image-lowlatency-hwe-16.04 4.8.0.56.27
linux-image-4.8.0-56-generic-lpae 4.8.0-56.61~16.04.1
linux-image-generic-lpae-hwe-16.04 4.8.0.56.27

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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

CVE-2017-1000364