Vulnerability · Published Jan 7, 2025 · Assigned by mozilla
CVE-2025-0239Alt-Svc ALPN validation failure when redirected
Medium 4.0
In plain English
A medium-severity improper certificate validation in Firefox from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)4.0Medium
Exploit odds (30 days)0.2%top 86.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | firefox | 128.6.0-1.el8_10 | ALSA-2025:0144 |
| AlmaLinux:9 | firefox | 128.6.0-1.el9_5 | ALSA-2025:0080 |
| AlmaLinux:9 | firefox-x11 | 128.6.0-1.el9_5 | ALSA-2025:0080 |
| AlmaLinux:8 | thunderbird | 128.6.0-3.el8_10.alma.1 | ALSA-2025:0281 |
| Debian:12 | firefox-esr | 128.6.0esr-1~deb12u1 | DEBIAN-CVE-2025-0239 |
| Debian:12 | firefox-esr | 128.6.0esr-1~deb12u1 | DSA-5839-1 |
| Debian:13 | firefox-esr | 128.6.0esr-1 | DEBIAN-CVE-2025-0239 |
| Debian:14 | firefox-esr | 128.6.0esr-1 | DEBIAN-CVE-2025-0239 |
| Debian:12 | thunderbird | 1:128.6.0esr-1~deb12u1 | DEBIAN-CVE-2025-0239 |
| Debian:12 | thunderbird | 1:128.6.0esr-1~deb12u1 | DSA-5841-1 |
| Debian:13 | thunderbird | 1:128.6.0esr-1 | DEBIAN-CVE-2025-0239 |
| Debian:14 | thunderbird | 1:128.6.0esr-1 | DEBIAN-CVE-2025-0239 |
| Rocky Linux:8 | firefox | 0:128.6.0-1.el8_10 | RLSA-2025:0144 |
| Ubuntu:22.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2025-0239 |
| Ubuntu:24.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2025-0239 |
| Ubuntu:24.04:LTS | mozjs115 | no fix listed | UBUNTU-CVE-2025-0239 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2025-0239 |
| Ubuntu:22.04:LTS | mozjs91 | no fix listed | UBUNTU-CVE-2025-0239 |
| Ubuntu:22.04:LTS | thunderbird | 1:140.7.1+build1-0ubuntu0.22.04.1 | UBUNTU-CVE-2025-0239 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | see references |
| Mozilla | Thunderbird | see references |
Weakness: CWE-295 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1929156
- https://www.mozilla.org/security/advisories/mfsa2025-01/
- https://www.mozilla.org/security/advisories/mfsa2025-02/
- https://www.mozilla.org/security/advisories/mfsa2025-04/
- https://www.mozilla.org/security/advisories/mfsa2025-05/
- https://lists.debian.org/debian-lts-announce/2025/01/msg00004.html