Critical Malicious Code Vulnerability in @posthog/plugin-server Package
Summary
MAL-2025-190947: Malicious code in @posthog/plugin-server (npm). Affects @posthog/plugin-server versions 1.10.8. No fix is published. How to fix ↓
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Background
The @posthog/plugin-server package is a Node.js library designed for integrating and managing plugins within the PostHog analytics platform. It allows developers to extend the functionality of PostHog by creating custom plugins. However, this package has been found to contain malicious code, posing a significant security risk to any system utilizing it.
Vulnerability Detail
The vulnerability originates from the inclusion of malicious code within the @posthog/plugin-server package. This code can compromise any computer that has the package installed, allowing unauthorized access to sensitive information such as secrets and keys. The malicious nature of this code is classified under CWE-506, indicating that it appears to be intentionally harmful. The ramifications of this vulnerability are severe, as it can lead to full control of the affected system by an external entity.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall @posthog/plugin-serverIf it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.
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Workaround
As a workaround, ensure that the @posthog/plugin-server package is uninstalled from your project. You can do this by running the following command in your terminal: npm uninstall @posthog/plugin-server. Additionally, monitor your systems for any unusual activity and consider using security tools to scan for remaining threats.
Conclusion
The discovery of malicious code within the @posthog/plugin-server package presents a critical security threat. Immediate action is required to mitigate risks, including uninstalling the package and rotating sensitive information. Utilizing tools like Vulert can help in monitoring for such vulnerabilities in the future.
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FAQ
Immediately uninstall the package and rotate any sensitive information stored on the affected system.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time. Check your application using the Vulert playground at Vulert Scanner.
Failure to address this vulnerability can lead to unauthorized access to sensitive data and potential control over your system by malicious actors.
Currently, the best course of action is to remove the package entirely, as the presence of malicious code indicates a serious compromise.
Regularly audit your dependencies, use tools like Vulert for monitoring, and stay updated on security advisories related to the packages you use.
References
Related vulnerabilities
Recent vulnerabilities recorded for @posthog/plugin-server.
