CVE-2021-3142
Fix: mautic/mautic@ba31db2CVE-2021-3142 is a security vulnerability in mautic/core. O3 Security confirms whether CVE-2021-3142 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
XSS in Mautic
Real-World Exposure
mautic/core🐘mautic/coreReal-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
This is a cross-site scripting vulnerability relating to creating/editing a company which requires the user to be logged in as an administrator to be executed.
This vulnerability was reported by Dardan Prebreza at Bishop Fox.
Patches
Upgrade to 3.2.4 or 2.16.5.
Link to patch for 2.x versions: https://github.com/mautic/mautic/compare/2.16.4...2.16.5.diff
Link to patch for 3.x versions: https://github.com/mautic/mautic/compare/3.2.2...3.2.4.diff
Workarounds
None
References
https://www.mautic.org/blog/community/security-release-all-versions-mautic-prior-2-16-5-and-3-2-4
For more information
If you have any questions or comments about this advisory:
- Post in https://forum.mautic.org/c/support
- Email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | mautic/core | ≥ 3.0.0&&< 3.2.4 | 3.2.4 |
| 🐘Packagist | mautic/core | ≥ 2.0.0&&< 2.16.5 | 2.16.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mautic/core. 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 mautic/core to 3.2.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-3142 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-2021-3142 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-2021-3142. 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-2021-3142 in your dependencies?
O3 detects CVE-2021-3142 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.