CVE-2020-21174 is a critical-severity (CVSS 9.8) Unrestricted File Upload vulnerability in feehi/cms. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for feehi/cms — see the affected versions and patch details below.
liufee CMS File Upload vulnerability
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2020-21174.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
feehi/cmsReal-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
File Upload vulenrability in liufee CMS v.2.0.7.1 allows a remote attacker to execute arbitrary code via the image suffix function.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | feehi/cms | all versions | 2.0.8.1composer require feehi/cms:^2.0.8.1 |
Affected Products
feehicmsfeehiResearch 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 feehi/cms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update feehi/cms to 2.0.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-21174 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-2020-21174 in your dependencies?
Find it across Packagist, including transitive dependencies.