Vulnerability in Mozilla Firefox
CVE-2021-43531
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.
EPSS: 0.003 (25.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N.
Affected products
- Mozilla Firefox — versions unspecified
Weakness classification (CWE)
References
- security@mozilla.org (x_refsource_MISC, Vendor Advisory)
- security@mozilla.org (Permissions Required, x_refsource_MISC, Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-43531?
- CVE-2021-43531 is a medium-severity vulnerability in Mozilla Firefox, classified under Origin Validation Error. CVSS score: 4.3/10. Published 2021-12-08.
- How severe is CVE-2021-43531?
- Medium severity. CVSS v3 base score is 4.3 out of 10.