Ubuntu Security Notice USN-293-1
9th June, 2006
gdm vulnerability
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 6.06 LTS
- Ubuntu 5.10
Details
If the admin configured a gdm theme that provided an user list, any
user could activate the gdm setup program by first choosing the setup
option from the menu, clicking on the user list and entering his own
(instead of root's) password. This allowed normal users to configure
potentially dangerous features like remote or automatic login.
Please note that this does not affect a default Ubuntu installation,
since the default theme does not provide an user list. In Ubuntu 6.06
you additionally have to have the "ConfigAvailable" setting enabled in
gdm.conf to be vulnerable (it is disabled by default).
Ubuntu 5.04 is not affected by this flaw.
Update instructions
The problem can be corrected by updating your system to the following package version:
- Ubuntu 6.06 LTS:
- gdm 2.14.6-0ubuntu2.1
- Ubuntu 5.10:
- gdm 2.8.0.5-0ubuntu1.2
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system upgrade is sufficient to effect the
necessary changes.