Critical Reverse Shell Vulnerability in eth-gas-oracle Package
Summary
MAL-2026-17786: Malicious code in eth-gas-oracle (RubyGems). Affects eth-gas-oracle versions 0.9.1. No fix is published. How to fix ↓
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Background
The eth-gas-oracle package is a RubyGem designed to provide gas price estimates for Ethereum transactions. It is utilized by developers to optimize transaction costs on the Ethereum network. However, this package has been compromised, embedding malicious code that poses a significant security risk to users who install it.
Vulnerability Detail
The vulnerability originates from a malicious payload embedded within the gem's native extension build script (ext/extconf.rb). This script base64-decodes the payload and executes it using eval in a detached child process during the gem installation. The payload establishes a reverse shell connection to a hardcoded IP address (45.138.12.177:8089), allowing the attacker to execute arbitrary commands on the victim's machine. The execution is gated by checks for certain environment variables and user artifacts, making it particularly insidious as it targets developers' environments while evading detection in CI/CD pipelines.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
bundle remove eth-gas-oracleIf it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.
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Workaround
As a temporary workaround, avoid installing the eth-gas-oracle package until a patched version is released. Additionally, consider using alternative packages for gas price estimation that do not have known vulnerabilities.
Conclusion
The eth-gas-oracle package contains a critical vulnerability that allows for remote command execution through a reverse shell. Users are advised to update or uninstall the package and utilize alternative solutions until a secure version is available. Continuous monitoring for vulnerabilities using tools like Vulert is essential for maintaining a secure development environment.
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FAQ
The vulnerability involves embedded malicious code that creates a reverse shell, allowing remote command execution on the installer's machine.
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If you have installed the package, it is recommended to uninstall it immediately and monitor your system for any suspicious activity.
The vulnerability is particularly targeted at developer environments, especially those containing sensitive artifacts like SSH keys and configuration files.
Ensure that your development environment is secure by using tools like Vulert to monitor for vulnerabilities, and avoid installing unverified packages.
