Directory traversal vulnerability in Chyrp 2.1 and earlier allows remote attackers to include and execute arbitrary local files via a ..%2F (encoded dot dot slash) in the action parameter to the default URI.
https://exchange.xforce.ibmcloud.com/vulnerabilities/68564
http://www.securityfocus.com/archive/1/518890/100/0/threaded
http://www.ocert.org/advisories/ocert-2011-001.html
http://securityreason.com/securityalert/8312