The msLoadQuery function in mapserv in MapServer 4.x before 4.10.4 and 5.x before 5.2.2 allows remote attackers to determine the existence of arbitrary files via a full pathname in the queryfile parameter, which triggers different error messages depending on whether this pathname exists.
https://www.redhat.com/archives/fedora-package-announce/2009-April/msg00170.html
https://www.redhat.com/archives/fedora-package-announce/2009-April/msg00147.html
http://www.securitytracker.com/id?1021952
http://www.securityfocus.com/bid/34306
http://www.securityfocus.com/archive/1/502271/100/0/threaded
http://www.positronsecurity.com/advisories/2009-000.html
http://www.debian.org/security/2009/dsa-1914
http://trac.osgeo.org/mapserver/ticket/2939
http://secunia.com/advisories/34603
http://secunia.com/advisories/34520
http://lists.osgeo.org/pipermail/mapserver-users/2009-March/060600.html