- Component Type: TYPO3 CMS
- Vulnerable subcomponent: Form Framework (ext:form)
- Release Date: January 22, 2019
- Vulnerability Type: Cross-Site Scripting
- Affected Versions: 8.5.0-8.7.22 and 9.0.0-9.5.3
- Severity: Medium
- Suggested CVSS v3.0: AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C
- CVE: not assigned yet
Failing to properly encode user input, frontend forms handled by the form framework (system extension “form”) are vulnerable to cross-site scripting.
Update to TYPO3 versions 8.7.23 or 9.5.4 that fix the problem described.
Strong security defaults - Manual actions required
Since using markup on purpose in form definitions is not possible anymore, this behavior has to be adjusted to make use of a proper Fluid template for the according ConfirmationFinisher - see https://docs.typo3.org/typo3cms/extensions/core/latest/Changelog/8.7.x/Feature-83405-AddConfirmationFinisherTemplate.html for details.
Thanks to TYPO3 core team member Susanne Moog who reported this issue and to TYPO3 core team member Ralf Zimmermann who fixed the issue.
All security related code changes are tagged so that you can easily look them up in our review system.