October 1, 2014

Critical Vulnerability is TYPO3-Core; Remote Code Execution

(LiveHacking.Com) – The TYPO3 development team has issued a warning about a critical vulnerability in the TYPO3 content management system.

According to TYPO3 security bulletins, a crafted request to a vulnerable TYPO3 installation will allow an attacker to load PHP code from an external source and to execute it on the TYPO3 installation. The security issue is due to insufficient validation of the AbstractController.php file’s BACK_PATH parameter that leads to remote code execution.

With reference to the TYPO3 security advisory, a vulnerable system will meet all the the following conditions:

  1. TYPO3 version 4.5.0 up to 4.5.8, 4.6.0 or 4.6.1 (+ development releases of 4.7 branch).
  2. The following PHP configuration variables set to “on”: register_globals (“off” by default, advised to be “off” in TYPO3SecurityGuide), allow_url_include (“off” by default) and allow_url_fopen (“on” by default)

The following solutions have been advised by the TYPO3 security advisory:

  1. Update to the TYPO3 version 4.5.9 or 4.6.2 that fixes the problem described.
  2. Set at least one of following PHP configuration variables to “off”: register_globals, allow_url_include and allow_url_fopen.
  3. Apply the securitypatch.
  4. Set up a mod_security rule: SecRule ARGS:BACK_PATH “^(https?|ftp)” “deny”.

Please view the TYPO3 security advisory for more information.