The chain-devkit npm package (version 1.0.0) executes a postinstall script that downloads a YAML configuration file from https://chain-devkit.com/config without version pinning, hash verification, or signature validation. The YAML is parsed with js-yaml 3.12.0's yaml.load, which supports !!js/function and !!js/regexp tags, enabling the creation of JavaScript Function objects during parsing. These objects are saved to disk and reloaded unsafely on require(), creating a persistent channel for remote code injection controlled by whoever manages chain-devkit.com. Although current code only reads scalar values, the presence of these Function objects means that arbitrary code execution could occur if future package versions or consumers invoke them. The package's publisher metadata is minimal and suspicious, reinforcing the likelihood of malicious intent.

This vulnerability allows an attacker controlling the chain-devkit.com domain to inject arbitrary JavaScript code into the installation and runtime environment of the chain-devkit package. While immediate code execution is not triggered by the current config content, the malicious code persists on disk and could be executed later by consumers or future package versions, potentially leading to remote code execution within the context of the affected environment.

No official patch or fix is currently available for this vulnerability. Users should avoid installing or using chain-devkit version 1.0.0. Since the package fetches configuration from an attacker-controlled domain without integrity checks, the safest mitigation is to remove the package from projects and replace it with trusted alternatives. Monitor vendor advisories for any future updates or official fixes. Do not rely on the package until a verified remediation is released.