Ubuntu Security Notice USN-325-1 – ruby1.8 suffer from flaws where the alias function, certain directory operations, and regular expressions did not correctly implement safe levels. Depending on the application these flaws might allow attackers to bypass safe level restrictions and perform unintended operations.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/48658/USN-325-1.txt
Source: https://packetstormsecurity.com/files/48658/Ubuntu-Security-Notice-325-1.html