Infopop UBB.Threads before 6.5.2 Beta allows remote attackers to include arbitrary files via the language parameter in a cookie followed by a null (%00) byte.
http://www.ubbcentral.com/boards/showflat.php/Cat/0/Number/42351/Main/42351/#Post42351
http://www.gulftech.org/?node=research&article_id=00084-06232005