4.0
MEDIUM
CVE-2025-0239
Mozilla Firefox TLS Certificate Validation Weakness
Description

When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability affects Firefox < 134, Firefox ESR < 128.6, Thunderbird < 134, and Thunderbird < 128.6.

INFO

Published Date :

Jan. 7, 2025, 4:15 p.m.

Last Modified :

Jan. 13, 2025, 10:15 p.m.

Source :

[email protected]

Remotely Exploitable :

No

Impact Score :

1.4

Exploitability Score :

2.5
Affected Products

The following products are affected by CVE-2025-0239 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Mozilla firefox
2 Mozilla firefox_esr
3 Mozilla thunderbird
4 Mozilla thunderbird_esr
: Total Affected Vendor : 1 | Products : 4
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-0239.

URL Resource
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/

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-0239 vulnerability anywhere in the article.

  • The Cyber Express
Critical Mozilla Vulnerabilities Prompt Urgent Updates for Firefox and Thunderbird Users

Mozilla Firefox and Thunderbird users are facing a series of high-severity vulnerabilities that could leave systems open to exploitation. The Indian Computer Emergency Response Team (CERT-In) issued a ... Read more

Published Date: Jan 21, 2025 (15 hours, 5 minutes ago)
CVE-2025-0245 CVE-2025-0244 CVE-2025-0242 CVE-2025-0239 CVE-2025-0237 CVE-2024-21893 CVE-2024-21887 CVE-2023-46805 CVE-2021-44228 CVE-2017-11882

The following table lists the changes that have been made to the CVE-2025-0239 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    Jan. 13, 2025

    Action Type Old Value New Value
    Changed Description When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability affects Firefox < 134, Firefox ESR < 128.6, Thunderbird < 134, and Thunderbird ESR < 128.6. When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability affects Firefox < 134, Firefox ESR < 128.6, Thunderbird < 134, and Thunderbird < 128.6.
  • CVE Modified by [email protected]

    Jan. 09, 2025

    Action Type Old Value New Value
    Changed Description When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability affects Firefox < 134 and Firefox ESR < 128.6. When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability affects Firefox < 134, Firefox ESR < 128.6, Thunderbird < 134, and Thunderbird ESR < 128.6.
    Added Reference https://www.mozilla.org/security/advisories/mfsa2025-04/
    Added Reference https://www.mozilla.org/security/advisories/mfsa2025-05/
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jan. 08, 2025

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
    Added CWE CWE-295
  • New CVE Received by [email protected]

    Jan. 07, 2025

    Action Type Old Value New Value
    Added Description When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability affects Firefox < 134 and Firefox ESR < 128.6.
    Added Reference https://bugzilla.mozilla.org/show_bug.cgi?id=1929156
    Added Reference https://www.mozilla.org/security/advisories/mfsa2025-01/
    Added Reference https://www.mozilla.org/security/advisories/mfsa2025-02/
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-0239 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2025-0239 weaknesses.

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
: