USN-868-1: GRUB 2 vulnerability
9 December 2009
GRUB 2 vulnerability
Releases
Packages
- grub2 -
Details
It was discovered that GRUB 2 did not properly validate passwords. An
attacker with physical access could conduct a brute force attack and bypass
authentication by submitting a 1 character password.
Update instructions
The problem can be corrected by updating your system to the following package versions:
Ubuntu 9.10
In general, a standard system upgrade is sufficient to effect the
necessary changes.
Users who have upgraded from GRUB Legacy to GRUB 2 and did not run
'upgrade-from-grub-legacy' (ie those who are still using Grub Legacy to
chainload into GRUB 2) will have to run the following command (possibly
adjusting 'hd0') to update GRUB 2's on disk core image:
$ sudo grub-install --no-floppy --grub-setup=/bin/true "(hd0)"