Ubuntu Security Notice USN-195-1 – The object oriented scripting language Ruby supports safely executing untrusted code with two mechanisms: safe level and taint flag on objects. Dr. Yutaka Oiwa discovered a vulnerability that allows Ruby methods to bypass these mechanisms. In systems which use this feature, this could be exploited to execute Ruby code beyond the restrictions specified in each safe level.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/40565/USN-195-1.txt
Source: https://packetstormsecurity.com/files/40565/Ubuntu-Security-Notice-195-1.html