Malicious Code Injection in css-ikomdq-polyfill Package
Summary
MAL-2026-17553: Malicious code in css-ikomdq-polyfill (npm). Affects css-ikomdq-polyfill versions 1.0.0. No fix is published. How to fix ↓
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Background
The css-ikomdq-polyfill package is designed to provide CSS polyfill functionalities for JavaScript applications. It aims to enhance compatibility across different browsers by allowing developers to use modern CSS features without worrying about browser support. However, this package has been found to contain malicious code that compromises the security of applications utilizing it.
Vulnerability Detail
The vulnerability originates from the inclusion of a malicious script, thunderboltRegistry.js, within the css-ikomdq-polyfill package. This script executes a series of commands upon being required, including system information retrieval commands like id, whoami, uname -a, and ifconfig/ip addr. It also reads the /etc/hosts file and sends the collected data to a hardcoded HTTP endpoint. The malicious code is designed to delete its own entries from require.cache, allowing it to re-run on each require, thus evading detection. This poses significant risks, including data leakage and unauthorized access to system information.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall css-ikomdq-polyfillIf it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.
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Workaround
As a temporary workaround, you can remove the css-ikomdq-polyfill package from your project until a secure version is released. You can do this by executing the following command: npm uninstall css-ikomdq-polyfill. Additionally, consider using alternative packages that provide similar functionalities without the associated risks.
Conclusion
The css-ikomdq-polyfill package contains a serious vulnerability due to embedded malicious code that can compromise system security. It is crucial for developers to take immediate action by updating or removing the package and to utilize tools like Vulert for ongoing monitoring of their dependencies.
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FAQ
The css-ikomdq-polyfill package is a JavaScript library that provides polyfill functionalities for CSS, enabling developers to use modern CSS features in applications that need to support older browsers.
The malicious code can lead to unauthorized data access, system information leakage, and potential exploitation of your application, compromising its security and integrity.
Yes, you can use Vulert, a tool that monitors and alerts for open-source vulnerabilities in your software. You can check your application for this vulnerability using the Vulert playground at Vulert Scanner without any signup.
If immediate updates are not possible, consider removing the package from your project and using alternative solutions until a secure version is available.
Regularly monitor your dependencies using tools like Vulert, which can alert you in real-time for any open-source vulnerabilities in your software.
