Component Type: TYPO3 CMS
Release Date: July 1, 2015
Vulnerable subcomponent: Frontend Logon
Vulnerability Type: Session Fixation
Affected Versions: Versions 6.2.0 to 6.2.13, 7.0.0 to 7.3.0
Suggested CVSS v2.0: AV:N/AC:H/Au:N/C:P/I:N/A:N/E:F/RL:OF/RC:C
CVE: not assigned yet
Problem Description: It has been discovered that TYPO3 is susceptible to session fixation. If a user authenticates while anonymous session data is present, the session id is not changed. This makes it possible for attackers to generate a valid session id, trick users into using this session id (e.g. by leveraging a different Cross-Site Scripting vulnerability) and then maybe getting access to an authenticated session.
Solution: Update to TYPO3 versions 6.2.14 or 7.3.1 that fix the problem described.
Credits: Thanks to Helmut Hummel 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.