[NPM:GHSA-9JXC-QJR9-VJXQ] electron-updater Code Signing Bypass on Windows

Severity High
Affected Packages 1
Fixed Packages 1
CVEs 1

Observations

The file packages/electron-updater/src/windowsExecutableCodeSignatureVerifier.ts implements the signature validation routine for Electron applications on Windows. It executes the following command in a new shell (process.env.ComSpec on Windows, usually C:\Windows\System32\cmd.exe):

https://github.com/electron-userland/electron-builder/blob/140e2f0eb0df79c2a46e35024e96d0563355fc89/packages/electron-updater/src/windowsExecutableCodeSignatureVerifier.ts#L35-L41

Because of the surrounding shell, a first pass by cmd.exe expands any environment variable found in command-line above.

Exploitation

This creates a situation where verifySignature() can be tricked into validating the certificate of a different file than the one that was just downloaded. If the step is successful, the malicious update will be executed even if its signature is invalid.

Impact

This attack assumes a compromised update manifest (server compromise, Man-in-the-Middle attack if fetched over HTTP, Cross-Site Scripting to point the application to a malicious updater server, etc.).

Patch

This vulnerability was patched in #8295, by comparing the path in the output of Get-AuthenticodeSignature with the intended one. The patch is available starting from 6.3.0-alpha.6.

Package Affected Version
pkg:npm/electron-updater <= 6.3.0-alpha.5
Package Fixed Version
pkg:npm/electron-updater = 6.3.0-alpha.6
ID
NPM:GHSA-9JXC-QJR9-VJXQ
Severity
high
URL
https://github.com/advisories/GHSA-9jxc-qjr9-vjxq
Published
2024-07-09T17:48:21
(4 days ago)
Modified
2024-07-09T21:41:16
(4 days ago)
Rights
NPM Security Team
Type Package URL Namespace Name / Product Version Distribution / Platform Arch Patch / Fix
Affected pkg:npm/electron-updater electron-updater <= 6.3.0-alpha.5
Fixed pkg:npm/electron-updater electron-updater = 6.3.0-alpha.6
# CVE Description CVSS EPSS EPSS Trend (30 days) Affected Products Weaknesses Security Advisories Exploits PoC Pubblication Date Modification Date
# CVE Description CVSS EPSS EPSS Trend (30 days) Affected Products Weaknesses Security Advisories PoC Pubblication Date Modification Date
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