Improper Certificate Validation in Mozilla Firefox and Firefox ESR - CVE-2025-0239
Published: January 7, 2025
Vulnerability identifier: #VU102425
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2025-0239
CWE-ID: CWE-295
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Mozilla
Affected software:
Mozilla Firefox
Firefox ESR
Mozilla Firefox
Firefox ESR
Detailed vulnerability description
The vulnerability allows a remote attacker to perform MitM attack.
The vulnerability exists due to Alt-Svc ALPN does not properly validate certificates when the original server is redirecting to an insecure site. A remote attacker can perform MitM attack.
How to mitigate CVE-2025-0239
Install updates from vendor's website.