TYPO3-EXT-SA-2021-008: Sensitive Information Disclosure in “Extbase Yaml Routes” (routes)

Categories: Development, Security Created by Torben Hansen
It has been discovered that the extension “Extbase Yaml Routes” (routes) is susceptible to Sensitive Information Disclosure.
  • Release Date: August 10, 2021
  • Component Type: Third party extension. This extension is not a part of the TYPO3 default installation.
  • Component: “Extbase Yaml Routes” (routes)
  • Vulnerability Type: Sensitive Information Disclosure
  • Affected Versions: 2.1.0 and below
  • Severity: Medium
  • Suggested CVSS: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N/E:F/RL:O/RC:C
  • References: CVE-2021-36793

Problem Description

When using the CsrfTokenViewHelper the extension discloses the user's session identifier to HTML output without processing of additional cryptographic hashing algorithms. This vulnerability cannot be exploited directly and occurs in combination with a chained attack - like for instance Cross Site Scripting  in the frontend output.


An updated version 2.1.1 is available from the TYPO3 extension manager, Packagist and at
Users of the extension are advised to update the extension as soon as possible.


Thanks to Security Team Member Oliver Hader for reporting the issue and to Serhii Borulko for providing an updated version of the extension.

General Advice

Follow the recommendations that are given in the TYPO3 Security Guide. Please subscribe to the typo3-announce mailing list.