{"id":"GHSA-9jxc-qjr9-vjxq","summary":"electron-updater Code Signing Bypass on Windows","details":"### Observations\nThe 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`):\n\nhttps://github.com/electron-userland/electron-builder/blob/140e2f0eb0df79c2a46e35024e96d0563355fc89/packages/electron-updater/src/windowsExecutableCodeSignatureVerifier.ts#L35-L41\n\nBecause of the surrounding shell, a first pass by `cmd.exe` expands any environment variable found in command-line above.\n\n### Exploitation\n\nThis 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. \n\n### Impact\n\nThis 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.).\n\n### Patch\n\nThis 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.","aliases":["CVE-2024-39698"],"modified":"2024-07-12T19:20:30Z","published":"2024-07-09T17:48:21Z","database_specific":{"nvd_published_at":"2024-07-09T18:15:10Z","cwe_ids":["CWE-154","CWE-295"],"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2024-07-09T17:48:21Z"},"references":[{"type":"WEB","url":"https://github.com/electron-userland/electron-builder/security/advisories/GHSA-9jxc-qjr9-vjxq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-39698"},{"type":"WEB","url":"https://github.com/electron-userland/electron-builder/pull/8295"},{"type":"WEB","url":"https://github.com/electron-userland/electron-builder/commit/ac2e6a25aa491c1ef5167a552c19fc2085cd427f"},{"type":"PACKAGE","url":"https://github.com/electron-userland/electron-builder"},{"type":"WEB","url":"https://github.com/electron-userland/electron-builder/blob/140e2f0eb0df79c2a46e35024e96d0563355fc89/packages/electron-updater/src/windowsExecutableCodeSignatureVerifier.ts#L35-L41"}],"affected":[{"package":{"name":"electron-updater","ecosystem":"npm","purl":"pkg:npm/electron-updater"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"6.3.0-alpha.6"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/07/GHSA-9jxc-qjr9-vjxq/GHSA-9jxc-qjr9-vjxq.json","last_known_affected_version_range":"\u003c= 6.3.0-alpha.5"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}