PHP remote file inclusion vulnerability in Classes/Controller/AbstractController.php in the workspaces system extension in TYPO3 4.5.x before 4.5.9, 4.6.x before 4.6.2, and development versions of 4.7 allows remote attackers to execute arbitrary PHP code via a URL in the BACK_PATH parameter.
http://www.openwall.com/lists/oss-security/2011/12/16/1
http://typo3.org/teams/security/security-bulletins/typo3-core/typo3-core-sa-2011-004/
http://typo3.org/fileadmin/security-team/bug32571/32571.diff