=========================================================================Ubuntu Security Notice USN-3255-1
April 04, 2017

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

- Ubuntu 16.10
- Ubuntu 16.04 LTS

Summary:

LightDM could be made to run programs as an administrator.

Software Description:
- lightdm: Display Manager

Details:

It was discovered that LightDM incorrectly handled home directory creation for
guest users. A local attacker could use this issue to gain ownership of
arbitrary directory paths and possibly gain administrative privileges.

Update instructions:

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

Ubuntu 16.10:
  lightdm                         1.19.5-0ubuntu1.1

Ubuntu 16.04 LTS:
  lightdm                         1.18.3-0ubuntu1.1

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-3255-1
  CVE-2017-7358

Package Information:
  https://launchpad.net/ubuntu/+source/lightdm/1.19.5-0ubuntu1.1
  https://launchpad.net/ubuntu/+source/lightdm/1.18.3-0ubuntu1.1