CVE-2021-21014
CRITICALCVE-2021-21014 is a critical-severity (CVSS 9.1) Unrestricted File Upload vulnerability in magento/community-edition. 2 public exploit references exist, so weaponization risk is real. O3 Security confirms whether CVE-2021-21014 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Magento vulnerable to a file upload restriction bypass
Real-World Exposure
magento/community-edition🐘magento/community-edition🐘magento/project-community-editionReal-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
Magento versions 2.4.1 (and earlier), 2.4.0-p1 (and earlier) and 2.3.6 (and earlier) are vulnerable to a file upload restriction bypass. Successful exploitation could lead to arbitrary code execution by an authenticated attacker. Access to the admin console is required for successful exploitation.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | magento/community-edition | all versions | 2.3.6-p1 |
| 🐘Packagist | magento/community-edition | ≥ 2.4.0&&< 2.4.2 | 2.4.2 |
| 🐘Packagist | magento/project-community-edition | all versions | No fix |
Research 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 magento/community-edition. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update magento/community-edition to 2.3.6-p1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-21014 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2021-21014 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2021-21014. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2021-21014 in your dependencies?
O3 detects CVE-2021-21014 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.