Multiple PHP remote file inclusion vulnerabilities in Kravchuk letter (K-letter) 1.0 allow remote attackers to execute arbitrary PHP code via a URL in the scdir parameter to (1) action.php, (2) subs.php, or (3) unsubs.php.
https://www.exploit-db.com/exploits/4034
https://exchange.xforce.ibmcloud.com/vulnerabilities/34738
http://www.vupen.com/english/advisories/2007/2091