Cross-Site Scripting in Fluid view helpers

> ### Meta
> * CVSS: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C (5.7)
> * CWE-79

Problem

It has been discovered that system extension Fluid (typo3/cms-fluid) of the TYPO3 core is vulnerable to cross-site scripting passing user-controlled data as argument to Fluid view helpers.

<f:form ... fieldNamePrefix="{payload}" />
<f:be.labels.csh ... label="{payload}" />
<f:be.menus.actionMenu ... label="{payload}" />

Solution

Update to TYPO3 versions 9.5.23 or 10.4.10 that fix the problem described.

Credits

Thanks to TYPO3 security team member Oliver Hader who reported this issue and to TYPO3 security team members Helmut Hummel & Oliver Hader who fixed the issue.

References

• TYPO3-CORE-SA-2020-010