Node.js native addons are compiled binary modules (.node files) that allow Node.js applications, including Electron apps, to execute native code written in C, C++, or Objective-C. Unlike JavaScript files, these binaries run with the same privileges as the Node.js process and can invoke system APIs directly, bypassing JavaScript sandbox restrictions. Electron applications commonly package their source code in ASAR archives, which can include an integrity check feature to prevent tampering by verifying a hash of the archive at runtime. However, native modules cannot be executed directly from within ASAR archives and are therefore stored in an unpacked directory (app.asar.unpacked), which is typically not protected by integrity checks. This creates an attack surface where a local attacker with write access can replace or modify these native modules, effectively hijacking the application to execute arbitrary native code, akin to DLL hijacking on Windows. The threat is exacerbated by the availability of tools such as the Electron ASAR Scanner, which identifies Electron apps lacking ASAR integrity protection, and NodeLoader, which compiles malicious native addons capable of launching macOS applications or shell commands. While ASAR integrity checking can mitigate tampering within the archive, it does not protect the unpacked native modules, leaving many Electron apps vulnerable. Exploitation requires local access but can lead to remote code execution, privilege escalation, or persistence within compromised systems. No known exploits are currently in the wild, but the threat is credible given the ease of compiling malicious native addons and the widespread use of Electron apps across platforms.

For European organizations, this vulnerability poses a significant risk primarily in environments where Electron-based applications are widely used, especially those that do not implement ASAR integrity checks or protect their unpacked native modules. Successful exploitation allows attackers with local access to execute arbitrary native code with the same privileges as the Electron app, potentially leading to privilege escalation, lateral movement, or persistent compromise. This can impact confidentiality by exposing sensitive data accessible to the compromised app, integrity by allowing unauthorized code execution or modification, and availability if malicious code disrupts application or system operations. Sectors relying heavily on Electron apps for desktop software, including finance, healthcare, and government agencies, may face elevated risks. The threat is particularly relevant in scenarios involving insider threats, compromised endpoints, or malware delivery that gains local file system access. Given the medium severity and local access requirement, the impact is more pronounced in organizations with lax endpoint security or insufficient application hardening. Additionally, the ability to bypass sandbox restrictions increases the attack surface for sophisticated adversaries targeting European enterprises.

European organizations should implement several targeted mitigations beyond generic advice: 1) Enable ASAR integrity checking in all Electron applications to ensure the archive contents are verified at runtime, preventing tampering within the archive. 2) Restrict write permissions on the app.asar.unpacked directory and the native .node files to trusted administrators only, preventing unauthorized modifications by local users or malware. 3) Employ application whitelisting and code signing enforcement to detect and block unauthorized native modules from loading. 4) Monitor file system integrity of unpacked native modules using endpoint detection and response (EDR) tools to alert on unexpected changes. 5) Conduct regular audits of Electron applications deployed in the environment to identify those lacking ASAR integrity or using native addons. 6) Educate developers and IT teams on the risks of native modules and encourage secure packaging practices, including minimizing use of native addons where possible. 7) Use sandboxing or containerization to limit the privileges of Electron apps, reducing the impact of potential code execution. 8) Implement strict endpoint security controls to prevent local privilege escalation and unauthorized file system access. These measures collectively reduce the attack surface and improve detection and prevention of exploitation attempts.