Component Type: TYPO3 CMS
Release Date: July 1, 2015
Vulnerable subcomponent: Backend Login
Vulnerability Type: Brute Force Protection Bypass
Affected Versions: Versions 6.2.0 to 6.2.13, 7.0.0 to 7.3.0
Suggested CVSS v2.0: AV:N/AC:L/Au:N/C:P/I:N/A:N/E:F/RL:OF/RC:C
CVE: not assigned yet
Problem Description: The backend login has a basic brute force protection implementation which pauses for 5 seconds if wrong credentials are given. This pause however could be bypassed by forging a special request, making brute force attacks on backend editor credentials more feasible.
Solution: Update to TYPO3 versions 6.2.14 or 7.3.1 that fix the problem described.
Important Note: These versions move the code to wait for 5 seconds to a place which is not possible to bypass. The consequence is, that frontend logon now also has this protection. Additionally a hook was implemented, making it possible to implement other brute force protection strategies or to remove the 5 second delay, which is the default behavior if no hook is present.
Example Hook registration:
$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_userauth.php']['postLoginFailureProcessing'] = 'My\\Package\\HookClass->hookMethod'
Credits: Thanks to Franz G. Jahn who discovered and reported the issue.
General Note: All security related code changes are tagged so that you can easily look them up on our review system.