CVE 2009-0843
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.
See the 
CVE page on Mitre.org
for more details.
