How severe is CVE-2021-3142?

No CVSS score has been assigned to CVE-2021-3142 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2021-3142?

CVE-2021-3142 affects the following packages: mautic/core (Packagist), mautic/core (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2021-3142?

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.

How do I detect CVE-2021-3142 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mautic/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-3142 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2021-3142 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-3142 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2021-3142 published, and has it been updated?

CVE-2021-3142 was published on January 29, 2021 and was last updated on November 30, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

Not in CISA KEV

CVE-2021-3142 — core

Fix: mautic/mautic@ba31db2

CVE-2021-3142 is a security vulnerability in mautic/core. A fix is available for mautic/core — see the affected versions and patch details below.

XSS in Mautic

Published

Jan 29, 2021

Updated

Nov 30, 2024

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 30, 2024 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

2 pkgs affected

🐘mautic/core🐘mautic/core

Real-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

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`mautic/core`	≥ 3.0.0&&< 3.2.4	3.2.4`composer require mautic/core:^3.2.4`
🐘Packagist	`mautic/core`	≥ 2.0.0&&< 2.16.5	2.16.5`composer require mautic/core:^2.16.5`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mautic/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### 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

O3 Security · Impact-Aware SCA

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