Secunia Security Advisory – Gary Smith has reported a vulnerability in CUPS, which can be exploited by malicious, local users to gain knowledge of sensitive information. The problem is that user credentials are stored in the error_log log file when printing to a shared printer via Samba.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/34600/sa12736.txt
Source: https://packetstormsecurity.com/files/34600/Secunia-Security-Advisory-12736.html