PHP remote file inclusion vulnerability in index.php in GNUBoard 3.39 and earlier allows remote attackers to execute arbitrary PHP code by modifying the doc parameter to reference a URL on a remote web server that contains the code.
https://exchange.xforce.ibmcloud.com/vulnerabilities/18494
http://www.securityfocus.com/bid/11948
http://sir.co.kr/?doc=bbs/gnuboard.php&bo_table=pds&page=1&wr_id=1871