CVE-2021-37627 — core-bundle
HIGHCVE-2021-37627 is a high-severity (CVSS 7.2) Improper Privilege Management vulnerability in contao/core-bundle. A fix is available for contao/core-bundle — see the affected versions and patch details below.
Privilege escalation via form generator
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-37627 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
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
Impact
It is possible for untrusted users to gain administrator rights with the form generator.
Installations are only affected if there are untrusted back end users with access to the form generator.
Patches
Update to Contao 4.4.56, 4.9.18 or 4.11.7.
Workarounds
Disable the form generator or disable the login for untrusted back end users.
References
https://contao.org/en/security-advisories/privilege-escalation-with-the-form-generator
For more information
If you have any questions or comments about this advisory, open an issue in contao/contao.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | contao/core-bundle | ≥ 4.0.0&&< 4.4.56 | 4.4.56composer require contao/core-bundle:^4.4.56 |
| 🐘Packagist | contao/core-bundle | ≥ 4.5.0&&< 4.9.18 | 4.9.18composer require contao/core-bundle:^4.9.18 |
| 🐘Packagist | contao/core-bundle | ≥ 4.10.0&&< 4.11.7 | 4.11.7composer require contao/core-bundle:^4.11.7 |
| 🐘Packagist | contao/contao | ≥ 4.0.0&&< 4.4.56 | 4.4.56composer require contao/contao:^4.4.56 |
| 🐘Packagist | contao/contao | ≥ 4.5.0&&< 4.9.18 | 4.9.18composer require contao/contao:^4.9.18 |
| 🐘Packagist | contao/contao | ≥ 4.10.0&&< 4.11.7 | 4.11.7composer require contao/contao:^4.11.7 |
Affected Products
contaocontaoDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for contao/core-bundle, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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
Close the privilege gap rather than the entry point: audit which accounts, roles and service identities can reach the affected operation, drop the component to the least privilege it actually needs, and review file and directory permissions created by earlier installs — a default left in place is what makes this reachable.
Frequently Asked Questions
Is CVE-2021-37627 in your dependencies?
Find it across Packagist, including transitive dependencies.