CVE-2021-43531Origin Validation Error in Mozilla Firefox

Severity
4.3MEDIUMNVD
EPSS
0.1%
top 75.35%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedDec 8
Latest updateDec 9

Description

When a user loaded a Web Extensions context menu, the Web Extension could access the post-redirect URL of the element clicked. If the Web Extension lacked the WebRequest permission for the hosts involved in the redirect, this would be a same-origin-violation leaking data the Web Extension should have access to. This was fixed to provide the pre-redirect URL. This is related to CVE-2021-43532 but in the context of Web Extensions. This vulnerability affects Firefox < 94.

CVSS vector

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

Affected Packages5 packages

debiandebian/firefox< firefox 94.0-1 (sid)
CVEListV5mozilla/firefoxunspecified94
NVDmozilla/firefox< 94.0
Ubuntumozilla/firefox< 94.0+build3-0ubuntu0.18.04.1+2
mozillamozilla/firefox

🔴Vulnerability Details

2
GHSA
GHSA-r6p5-8pxg-2vcp: When a user loaded a Web Extensions context menu, the Web Extension could access the post-redirect URL of the element clicked2021-12-09
OSV
CVE-2021-43531: When a user loaded a Web Extensions context menu, the Web Extension could access the post-redirect URL of the element clicked2021-12-08

📋Vendor Advisories

2
Debian
CVE-2021-43531: firefox - When a user loaded a Web Extensions context menu, the Web Extension could access...2021
Mozilla
Mozilla Foundation Security Advisory 2021-48: CVE-2021-43531