Mandriva Linux Security Advisory – Sebastian Krahmer of the SUSE Security Team discovered a flaw in the way Postfix dereferenced symbolic links. If a local user had write access to a mail spool directory without a root mailbox file, it could be possible for them to append arbitrary data to files that root had write permissions to. The updated packages have been patched to correct this issue.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/69151/MDVSA-2008-171.txt
Source: https://packetstormsecurity.com/files/69151/Mandriva-Linux-Security-Advisory-2008-171.html