CVE-2025-66558 affects Nextcloud Twofactor WebAuthn versions prior to 1.4.2 and 2.4.1. This vulnerability, a missing ownership check, allows an unauthenticated attacker to disassociate a user's 2FA WebAuthn device by guessing a long random string. While the attacker cannot authenticate as the victim, the victim will be prompted to register a new device upon their next login. Rated as Medium severity (CVSS 4.3), the attack requires no privileges and low complexity, but user interaction is needed (the attacker must guess the string). The potential impact is limited to low integrity, as it only removes the 2FA device, not granting unauthorized access. Currently, there is no evidence of active exploitation, and no public exploit code (Metasploit, Nuclei, ExploitDB) is available. Community discussion and media coverage for this CVE are minimal.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 1.0.0, < 1.4.2CPE matchmatch criteria | cpe:2.3:a:nextcloud:two-factor_webauthn:*:*:*:*:*:*:*:* | ||
>= 2.0.0, < 2.4.1CPE matchmatch criteria | cpe:2.3:a:nextcloud:two-factor_webauthn:*:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N
No social media mentions found for this CVE.
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.