Ubuntu Security Notice USN-738-1 – Diego Petten discovered that the Base64 encoding functions in GLib did not properly handle large strings. If a user or automated system were tricked into processing a crafted Base64 string, an attacker could possibly execute arbitrary code with the privileges of the user invoking the program.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/75781/USN-738-1.txt
Source: https://packetstormsecurity.com/files/75781/Ubuntu-Security-Notice-738-1.html