Directory traversal vulnerability in error.php in PostNuke 0.763 and earlier allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the PNSVlang (PNSV lang) cookie, as demonstrated by injecting PHP sequences into an Apache HTTP Server log file, which is then included by error.php.
https://www.exploit-db.com/exploits/2707
https://exchange.xforce.ibmcloud.com/vulnerabilities/29992
http://www.securityfocus.com/bid/21218