Absolute path traversal vulnerability in the get functionality in Anti-Spam SMTP Proxy (ASSP) allows remote authenticated users to read arbitrary files via (1) C:\ (Windows drive letter), (2) UNC, and possibly other types of paths in the file parameter.
https://exchange.xforce.ibmcloud.com/vulnerabilities/28392
http://www.vupen.com/english/advisories/2006/3289
http://www.securityfocus.com/bid/19545
http://secunia.com/advisories/21523
http://lists.grok.org.uk/pipermail/full-disclosure/2006-August/048853.html