# Exploit Title: Typo3 v4.5-4.7 - Remote Code Execution (RFI/LFI) # Date: 4th January 2012 # Author: MaXe # Software Link: https://typo3.org/download/ # Version: 4.5.0 up to 4.5.8, 4.6.0 and 4.6.1 (+ development releases of 4.7 branch) Typo3 v4.5-4.7 - Remote Code Execution (RFI/LFI) Versions Affected: 4.5.0 up to 4.5.8, 4.6.0 and 4.6.1 (+ development releases of 4.7 branch) Info: TYPO3 is a small to midsize enterprise-class Content Management Framework offering the best of both worlds: out-of-the-box operation with a complete set of standard modules and a clean and sturdy high-performance architecture accomodating virtually every kind of custom solution or extension. External Links: http://typo3.org/ Credits: BjÃrn Pedersen and Christian Toffolo who discovered and reported the issue and the Security Team member Helmut Hummel for providing the patch. (This advisory was rewritten by MaXe @InterN0T to offer a quick overview of the vulnerability, including the removal of all irrelevant and untrue details. -:: The Advisory ::- Requirements for any RCE: - register_globals in the php.ini MUST be enabled (if the exploit fails against a supposed to be vulnerable version, this is why. This setting is often disabled by default.) Requirements for RFI: - allow_url_include has to be enabled (It's often "off" by default.) Proof of Concept: By browsing to a script / page, that uses the following file: typo3/sysext/workspaces/Classes/Controller/AbstractController.php (direct access may not be allowed) It is possible to include PHP code to be executed via the "BACK_PATH" global variable. This can be accessed in ways like: AbstractController.php?BACK_PATH=LFI/RFI%00 The vulnerable piece of code: require_once($GLOBALS['BACK_PATH'] . 'template.php'); Demonstrates, that it is necessary to append a null-byte ( %00 ) after the maliciously crafted input / URL. (Unless your remote file if applicable, is named something.template.php) -:: Solution ::- * Update to the latest version of Typo3 OR change the vulnerable piece of code to: require_once(PATH_site . TYPO3_mainDir . 'template.php'); References: - http://typo3.org/fileadmin/security-team/bug32571/32571.diff - https://typo3.org/teams/security/security-bulletins/typo3-core/typo3-core-sa-2011-004/ - http://news.typo3.org/news/article/important-security-bulletin-pre-announcement-2/