Arand Nash discovered that applications linked to GLib (e.g. Nautilus) did not correctly copy symlinks. If a user copied symlinks with GLib, the symlink target files would become world-writable, allowing local attackers to gain access to potentially sensitive information.
The problem can be corrected by updating your system to the following package versions:
5 October 2009
A security issue affects these releases of Ubuntu and its derivatives:
Arand Nash discovered that applications linked to GLib (e.g. Nautilus) did not correctly copy symlinks. If a user copied symlinks with GLib, the symlink target files would become world-writable, allowing local attackers to gain access to potentially sensitive information.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system upgrade you need to restart your session to effect the necessary changes.