XML External Entity (XXE) Processing in TYPO3 Core

Categories: TYPO3 CMS 123 Created by Nicole Cordes
It has been discovered, that TYPO3 is susceptible to XML External Entity Processing

Component Type: TYPO3 CMS

Release Date: February 23, 2016

Vulnerable subcomponent: TYPO3 CMS

Vulnerability Type: XML External Entity Processing

Affected Versions: Versions 6.2.0 to 6.2.18 and 7.6.0 to 7.6.3

Severity: Low

Suggested CVSS v2.0: AV:N/AC:M/Au:N/C:P/I:P/A:P/E:P/RL:O/RC:C

CVE: not assigned yet

Problem Description: All XML processing within the TYPO3 CMS are vulnerable to XEE processing. This can lead to load internal and/or external (file) content within an XML structure. Furthermore it is possible to inject arbitrary files for an XML Denial of Service attack. For more information on that topic see https://www.owasp.org/index.php/XML_External_Entity_(XXE)_Processing.

Solution: Update to TYPO3 versions 6.2.19 or 7.6.4 that fix the problem described.

Important Note: Systems using a PHP version with libxml2 >= 2.9 should be protected by default. Since version 2.9 the library changed its behavior to disallow external entity processing by default.

Credits: Thanks to security team member Marcus Krause 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.