Ubuntu Security Notice 900-1 – Emmanouel Kellinis discovered that Ruby did not properly handle certain string operations. An attacker could exploit this issue and possibly execute arbitrary code with application privileges. Giovanni Pellerano, Alessandro Tanasi, and Francesco Ongaro discovered that Ruby did not properly sanitize data written to log files. An attacker could insert specially-crafted data into log files which could affect certain terminal emulators and cause arbitrary files to be overwritten, or even possibly execute arbitrary commands. It was discovered that Ruby did not properly handle string arguments that represent large numbers. An attacker could exploit this and cause a denial of service. This issue only affected Ubuntu 9.10.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/86361/USN-900-1.txt
Source: https://packetstormsecurity.com/files/86361/Ubuntu-Security-Notice-900-1.html