CVE-2021-42171 is a high-severity (CVSS 7.2) Unrestricted File Upload vulnerability in tribalsystems/zenario. 2 public exploit references exist, so weaponization risk is real. A fix is available for tribalsystems/zenario — see the affected versions and patch details below.
Unrestricted Upload of File with Dangerous Type in Zenario CMS
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-42171 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
tribalsystems/zenarioReal-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
Zenario CMS 9.0.54156 is vulnerable to File Upload. The web server can be compromised by uploading and executing a web-shell which can run commands, browse system files, browse local resources, attack other servers, and exploit the local vulnerabilities, and so forth.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | tribalsystems/zenario | all versions | 9.0.55143composer require tribalsystems/zenario:^9.0.55143 |
Affected Products
zenariotribalsystemsResearch 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 tribalsystems/zenario, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tribalsystems/zenario to 9.0.55143 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-42171 is resolved across your whole dependency graph.
Workarounds
Treat uploaded files as untrusted until proven otherwise: validate the actual content type rather than the supplied extension, store uploads outside the web root on a volume mounted without execute permission, and rename them to server-generated identifiers so an attacker cannot choose the path a request will later resolve.
Frequently Asked Questions
Is CVE-2021-42171 in your dependencies?
Find it across Packagist, including transitive dependencies.