CVE-2020-15241 is a medium-severity (CVSS 6.1) Open Redirect vulnerability in typo3fluid/fluid. 2 public exploit references exist, so weaponization risk is real. A fix is available for typo3fluid/fluid — see the affected versions and patch details below.
Cross-Site Scripting in ternary conditional operator
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2020-15241 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,987 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
typo3fluid/fluid🐘typo3fluid/fluid🐘typo3fluid/fluid🐘typo3fluid/fluid🐘typo3fluid/fluid🐘typo3fluid/fluid🐘typo3fluid/fluid🐘typo3/cms-core+3 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Meta
- CVSS:
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C(5.0)- CWE-79
:information_source: This vulnerability has been fixed in May 2019 already, CVE and GHSA were assigned later in October 2020
Problem
It has been discovered that the Fluid Engine (package typo3fluid/fluid) is vulnerable to cross-site scripting when making use of the ternary conditional operator in templates like the following.
{showFullName ? fullName : defaultValue}
Solution
Update to versions 2.0.5, 2.1.4, 2.2.1, 2.3.5, 2.4.1, 2.5.5 or 2.6.1 of this typo3fluid/fluid package that fix the problem described.
Updated versions of this package are bundled in following TYPO3 (typo3/cms-core) releases:
- TYPO3 v8.7.25 (using
typo3fluid/fluidv2.5.5) - TYPO3 v9.5.6 (using
typo3fluid/fluidv2.6.1)
Credits
Thanks to Bill Dagou who reported this issue and to TYPO3 core merger Claus Due who fixed the issue.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | typo3fluid/fluid | ≥ 2.0.0&&< 2.0.5 | 2.0.5composer require typo3fluid/fluid:^2.0.5 |
| 🐘Packagist | typo3fluid/fluid | ≥ 2.1.0&&< 2.1.4 | 2.1.4composer require typo3fluid/fluid:^2.1.4 |
| 🐘Packagist | typo3fluid/fluid | ≥ 2.2.0&&< 2.2.1 | 2.2.1composer require typo3fluid/fluid:^2.2.1 |
| 🐘Packagist | typo3fluid/fluid | ≥ 2.3.0&&< 2.3.5 | 2.3.5composer require typo3fluid/fluid:^2.3.5 |
| 🐘Packagist | typo3fluid/fluid | ≥ 2.4.0&&< 2.4.1 | 2.4.1composer require typo3fluid/fluid:^2.4.1 |
| 🐘Packagist | typo3fluid/fluid | ≥ 2.5.0&&< 2.5.5 | 2.5.5composer require typo3fluid/fluid:^2.5.5 |
Affected Products
fluid enginetypo3typo3typo3Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3fluid/fluid, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update typo3fluid/fluid to 2.0.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-15241 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2020-15241 in your dependencies?
Find it across Packagist, including transitive dependencies.