Description
Nextcloud Twofactor WebAuthn is the WebAuthn Two-Factor Provider for Nextcloud. Prior to 1.4.2 and 2.4.1, a missing ownership check allowed an attack to take-away a 2FA webauthn device when correctly guessing a 80-128 character long random string of letters, numbers and symbols. The victim would then be prompted to register a new device on the next login. The attacker can not authenticate as the victim. This vulnerability is fixed in 1.4.2 and 2.4.1.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| nextcloud | security-advisories | < 1.4.2, >= 2.0.0-beta.1, < 2.4.1 | — |
Advisories 1
- WID-SEC-2025-2757 Nextcloud (Contacts, Talk, Deck und Twofactor WebAuthn): Mehrere Schwachstellen BSI CERT-Bund (WID) · Dec 7, 2025