mapserv.c in mapserv in MapServer before 4.10.6 and 5.x before 5.6.4 does not properly restrict the use of CGI command-line arguments that were intended for debugging, which allows remote attackers to have an unspecified impact via crafted arguments.
https://exchange.xforce.ibmcloud.com/vulnerabilities/60852
http://www.securityfocus.com/bid/41855
http://trac.osgeo.org/mapserver/ticket/3485
http://marc.info/?l=oss-security&m=127973754121922&w=2
http://marc.info/?l=oss-security&m=127973381215859&w=2
http://lists.osgeo.org/pipermail/mapserver-users/2010-July/066052.html