CVE-2025-66558

LOW

Nextcloud Twofactor WebAuthn <1.4.2, <2.4.1 - Info Disclosure

Title source: llm

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.

References (4)

Core 4

Core References

Patch, Vendor Advisory x_refsource_confirm

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-fr8x-mvjg-wf9q

Patch x_refsource_misc

https://github.com/nextcloud/twofactor_webauthn/commit/5d2302166d31ee2e01b2e21556bd5372156da13d

View Patch ZIP pw:eip

Permissions Required, Vendor Advisory x_refsource_misc

https://hackerone.com/reports/3360354

Issue Tracking, Patch x_refsource_misc

https://github.com/nextcloud/twofactor_webauthn/pull/881

Scores

CVSS v3 3.1

EPSS 0.0003

EPSS Percentile 6.9%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-639

Status published

Products (1)

nextcloud/two-factor_webauthn 1.0.0 - 1.4.2

Published Dec 05, 2025

Tracked Since Feb 18, 2026