CVE-2025-5020Improper Authorization in Handler for Custom URL Scheme in Mozilla Firefox

Severity
4.3MEDIUMNVD
EPSS
0.2%
top 60.21%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
Timeline
PublishedMay 21

Description

Opening maliciously-crafted URLs in Firefox from other apps such as Safari could have allowed attackers to spoof website addresses if the URLs utilized non-HTTP schemes used internally by the Firefox iOS client. This vulnerability was fixed in Firefox for iOS 139.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:NExploitability: 2.8 | Impact: 1.4

Affected Packages1 packages

NVDmozilla/firefox< 139.0

🔴Vulnerability Details

3
GHSA
GHSA-7mfw-wgr7-m3jg: Opening maliciously-crafted URLs in Firefox from other apps such as Safari could have allowed attackers to spoof website addresses if the URLs utilize2025-05-21
OSV
CVE-2025-5020: Opening maliciously-crafted URLs in Firefox from other apps such as Safari could have allowed attackers to spoof website addresses if the URLs utilize2025-05-21
CVEList
Links using non-HTTP schemes opened from other apps such as Safari could have allowed spoofing of website addresses2025-05-21

📋Vendor Advisories

2
Debian
CVE-2025-5020: firefox - Opening maliciously-crafted URLs in Firefox from other apps such as Safari could...2025
Mozilla
Mozilla Foundation Security Advisory 2025-39: CVE-2025-5020
CVE-2025-5020 — Mozilla Firefox vulnerability | cvebase