USN-2836-1: GRUB vulnerability

15 December 2015

grub2 vulnerability

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

  • Ubuntu 15.10
  • Ubuntu 15.04
  • Ubuntu 14.04 LTS
  • Ubuntu 12.04 LTS


GRUB password protection can be bypassed.

Software Description

  • grub2 - GRand Unified Bootloader


Hector Marco and Ismael Ripoll discovered that GRUB incorrectly handled the backspace key when configured to use authentication. A local attacker could use this issue to bypass GRUB password protection.

Update instructions

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

Ubuntu 15.10
grub2-common - 2.02~beta2-29ubuntu0.2
Ubuntu 15.04
grub2-common - 2.02~beta2-22ubuntu1.4
Ubuntu 14.04 LTS
grub2-common - 2.02~beta2-9ubuntu1.6
Ubuntu 12.04 LTS
grub2-common - 1.99-21ubuntu3.19

To update your system, please follow these instructions:

After a standard system update you need to reboot your computer to make all the necessary changes.