Directory traversal vulnerability in download2.php in cattaDoc 2.21, and possibly other versions including 3.0, allows remote attackers to read arbitrary files via a .. (dot dot) in the fn1 parameter.
https://www.exploit-db.com/exploits/3677
https://exchange.xforce.ibmcloud.com/vulnerabilities/33474
http://www.vupen.com/english/advisories/2007/1297
http://www.securityfocus.com/bid/23390