Ubuntu Security Notice USN-799-1 – It was discovered that the D-Bus library did not correctly validate signatures. If a local user sent a specially crafted D-Bus key, they could spoof a valid signature and bypass security policies.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/79139/USN-799-1.txt
Source: https://packetstormsecurity.com/files/79139/Ubuntu-Security-Notice-799-1.html