CVE-2021-37627
HIGHCVE-2021-37627 is a high-severity (CVSS 7.2) Improper Privilege Management vulnerability in contao/core-bundle. O3 Security confirms whether CVE-2021-37627 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Privilege escalation via form generator
Real-World Exposure
contao/core-bundle🐘contao/core-bundle🐘contao/core-bundle🐘contao/contao🐘contao/contao🐘contao/contaoReal-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
Contao is an open source CMS that allows creation of websites and scalable web applications. In affected versions it is possible to gain privileged rights in the Contao back end. Installations are only affected if they have untrusted back end users who have access to the form generator. All users are advised to update to Contao 4.4.56, 4.9.18 or 4.11.7. As a workaround users may disable the form generator or disable the login for untrusted back end users.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | contao/core-bundle | ≥ 4.0.0&&< 4.4.56 | 4.4.56 |
| 🐘Packagist | contao/core-bundle | ≥ 4.5.0&&< 4.9.18 | 4.9.18 |
| 🐘Packagist | contao/core-bundle | ≥ 4.10.0&&< 4.11.7 | 4.11.7 |
| 🐘Packagist | contao/contao | ≥ 4.0.0&&< 4.4.56 | 4.4.56 |
| 🐘Packagist | contao/contao | ≥ 4.5.0&&< 4.9.18 | 4.9.18 |
| 🐘Packagist | contao/contao | ≥ 4.10.0&&< 4.11.7 | 4.11.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for contao/core-bundle. 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 contao/core-bundle to 4.4.56 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-37627 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-2021-37627 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-2021-37627. 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-2021-37627 in your dependencies?
O3 detects CVE-2021-37627 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.