Improperly implemented security check for standard in Mozilla Firefox and Firefox for Android - CVE-2025-6433
Published: June 24, 2025
Vulnerability identifier: #VU111894
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2025-6433
CWE-ID: CWE-358
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Mozilla
Affected software:
Mozilla Firefox
Firefox for Android
Mozilla Firefox
Firefox for Android
Detailed vulnerability description
The vulnerability allows a remote attacker to gain access to sensitive information.
The vulnerability exists due to an error when handling invalid TLS certificates. If a user visited a webpage with an invalid TLS certificate, and granted an exception, the webpage was able to provide a WebAuthn challenge that the user would be prompted to complete. This is in violation of the WebAuthN spec which requires "a secure transport established without errors".
How to mitigate CVE-2025-6433
Install updates from vendor's website.