Directory traversal vulnerability in inc/lib/language.lib.php in Claroline before 1.8.6 allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the language parameter.
http://www.vupen.com/english/advisories/2007/3045
http://www.claroline.net/wiki/index.php/Changelog_1.8.x#Security
http://www.claroline.net/forum/viewtopic.php?t=13533