XSS in Typo3 Fluid

CVE-2020-26216

TYPO3 Fluid before versions 2.0.8, 2.1.7, 2.2.4, 2.3.7, 2.4.4, 2.5.11 and 2.6.10 is vulnerable to Cross-Site Scripting. Three XSS vulnerabilities have been detected in Fluid: 1. TagBasedViewHelper allowed XSS through maliciously crafted additionalAttributes arrays by creating keys with attribute-closing quotes followed by HTML. When rendering such attributes, TagBuilder would not escape the keys. 2. ViewHelpers which used the CompileWithContentArgumentAndRenderStatic trait, and which declared escapeOutput = false, would receive the content argument in unescaped format. 3. Subclasses of AbstractConditionViewHelper would receive the then and else arguments in unescaped format. Update to versions 2.0.8, 2.1.7, 2.2.4, 2.3.7, 2.4.4, 2.5.11 or 2.6.10 of this typo3fluid/fluid package that fix the problem described. More details are available in the linked advisory.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.010 (60.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.0 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N.

Affected products

  • Typo3 Fluid — versions >= 2.0.0, < 2.0.8, >= 2.1.0, < 2.1.7, >= 2.2.0, < 2.2.4

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2020-26216?
CVE-2020-26216 is a high-severity vulnerability in Typo3 Fluid, classified under Cross-site Scripting. CVSS score: 8.0/10. Published 2020-11-17.
How severe is CVE-2020-26216?
High severity. CVSS v3 base score is 8.0 out of 10.