CVE-2025-66558

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.

CVSS v3 3.1 LOW

3.1^/10

CVSS v3 : LOW

Vector :

Exploitability : 1.6 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-fr8x-mvjg-wf9q	Patch Vendor Advisory
https://github.com/nextcloud/twofactor_webauthn/commit/5d2302166d31ee2e01b2e21556bd5372156da13d	Patch
https://github.com/nextcloud/twofactor_webauthn/pull/881	Issue Tracking Patch
https://hackerone.com/reports/3360354	Permissions Required Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:nextcloud:two-factor_webauthn::::::::
	cpe:2.3:a:nextcloud:two-factor_webauthn::::::::

History

No history.

Information

Published : 2025-12-05 18:15

Updated : 2025-12-09 16:44

NVD link : CVE-2025-66558

Mitre link : CVE-2025-66558

CVE.ORG link : CVE-2025-66558

JSON object : View

Products Affected

nextcloud

two-factor_webauthn

CWE

CWE-639

Authorization Bypass Through User-Controlled Key

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