GDM could be made to crash or run programs as the administrator.
A use-after-free was discovered in GDM. A local user could exploit this to cause a denial of service, or potentially execute arbitrary code as the administrator.
13 August 2018
A security issue affects these releases of Ubuntu and its derivatives:
GDM could be made to crash or run programs as the administrator.
A use-after-free was discovered in GDM. A local user could exploit this to cause a denial of service, or potentially execute arbitrary code as the administrator.
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 update you need to reboot your computer to make all the necessary changes.