Component Type: TYPO3 CMS
Release Date: July 19, 2016
Vulnerability Type: Cross-Site Scripting
Affected Versions: 7.6.0 to 7.6.9 and 8.0.0 to 8.2.0
Suggested CVSS v2.0: AV:N/AC:L/Au:S/C:N/I:P/A:N/E:F/RL:O/RC:C
CVE: not assigned yet
Problem Description: TYPO3 ships example code from mso/idna-convert library in the vendor folder, which is vulnerable to Cross-Site Scripting.
Solution: Update to TYPO3 versions 7.6.10 or 8.2.1 that fix the problem described.
Alternative Solution: Make sure to not expose the vendor directory to the publicly accessible document root. In composer managed installation, make sure to configure a dedicated web folder. In general it is recommended to not expose the complete typo3_src sources folder in the document root.
Credits: Thanks to Frank Huber 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.