CVE-2024-39698
📋 TL;DR
This vulnerability in electron-updater allows attackers to bypass Windows executable signature verification during Electron app updates. By exploiting environment variable expansion in the verification command, attackers can trick the system into validating a different file's certificate, potentially executing malicious updates. This affects all Electron applications using vulnerable versions of electron-updater for Windows updates.
💻 Affected Systems
- electron-updater
- Electron applications using electron-updater
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise through execution of arbitrary malicious code with application privileges, potentially leading to data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Malicious update execution leading to application compromise, credential theft, or lateral movement within the network.
If Mitigated
Update failure or detection through proper network controls and monitoring, preventing malicious update delivery.
🎯 Exploit Status
Exploitation requires compromising update infrastructure or intercepting update traffic, but the bypass technique itself is straightforward once those conditions are met.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.3.0-alpha.6 and later
Vendor Advisory: https://github.com/electron-userland/electron-builder/security/advisories/GHSA-9jxc-qjr9-vjxq
Restart Required: Yes
Instructions:
1. Update electron-updater dependency to version 6.3.0-alpha.6 or later. 2. Rebuild and redeploy Electron applications. 3. Ensure all client applications are updated to the patched version.
🔧 Temporary Workarounds
Disable automatic updates
allTemporarily disable automatic updates until patching is complete
Set autoUpdater.autoDownload = false in Electron application code
Use HTTPS for update servers
allEnsure update manifests and binaries are served exclusively over HTTPS
🧯 If You Can't Patch
- Implement strict network controls to prevent MITM attacks on update traffic
- Use application allowlisting to prevent execution of unauthorized binaries
🔍 How to Verify
Check if Vulnerable:
Check package.json or package-lock.json for electron-updater version below 6.3.0-alpha.6Check Version:
npm list electron-updaterVerify Fix Applied:
Verify electron-updater version is 6.3.0-alpha.6 or higher in package dependencies📡 Detection & Monitoring
Log Indicators:
- Failed signature verification attempts
- Update downloads from unexpected sources
- Unusual process execution following updates
Network Indicators:
- HTTP connections to update servers (should be HTTPS)
- Update downloads from non-standard domains or IPs
SIEM Query:
Process creation where parent process is Electron application AND command line contains update-related strings AND signature verification logs show anomalies🔗 References
- https://github.com/electron-userland/electron-builder/blob/140e2f0eb0df79c2a46e35024e96d0563355fc89/packages/electron-updater/src/windowsExecutableCodeSignatureVerifier.ts#L35-L41
- https://github.com/electron-userland/electron-builder/commit/ac2e6a25aa491c1ef5167a552c19fc2085cd427f
- https://github.com/electron-userland/electron-builder/pull/8295
- https://github.com/electron-userland/electron-builder/security/advisories/GHSA-9jxc-qjr9-vjxq
- https://github.com/electron-userland/electron-builder/blob/140e2f0eb0df79c2a46e35024e96d0563355fc89/packages/electron-updater/src/windowsExecutableCodeSignatureVerifier.ts#L35-L41
- https://github.com/electron-userland/electron-builder/commit/ac2e6a25aa491c1ef5167a552c19fc2085cd427f
- https://github.com/electron-userland/electron-builder/pull/8295
- https://github.com/electron-userland/electron-builder/security/advisories/GHSA-9jxc-qjr9-vjxq
