Component Type: TYPO3 CMS
Release Date: November 22, 2016
Vulnerable subcomponent: Core
Vulnerability Type: Path Traversal
Affected Versions: Versions 6.2.0 to 6.2.28, 7.6.0 to 7.6.12 and 8.0.0 to 8.4.0
Suggested CVSS v2.0: AV:N/AC:H/Au:N/C:P/I:N/A:N/E:P/RL:O/RC:C
CVE: not assigned yet
Problem Description: Due to a too loose type check in an API method, attackers could bypass the directory traversal check by providing an invalid UTF-8 encoding sequence.
Solution: Update to TYPO3 versions 6.2.29, 7.6.13 or 8.4.1 that fix the problem described.
Important Note: TYPO3 installations having file names or folder names containing invalid UTF-8 encoding, now trigger an error, when accessing these files. It is recommended to rename these files to contain valid encoding sequences.
Credits: Thanks to Gerrit Venema who discovered and reported the issue.
General Advice: Follow the recommendations that are given in the TYPO3 Security Guide. Please subscribe to the typo3-announce mailing list.
General Note: All security related code changes are tagged so that you can easily look them up on our review system.