Ubuntu Security Notice 3934-2 - USN-3934-1 fixed a vulnerability in Policykit. This update provides the corresponding update for Ubuntu 12.04 ESM. It was discovered that PolicyKit incorrectly relied on the fork system call in the Linux kernel being atomic. A local attacker could possibly use this issue to gain access to services that have cached authorizations. Various other issues were also addressed.
13db2b49515621a4f2d04fc157919dafa07b9c4e91f83f5c1eb644a170dc9033