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.

• CWE-346

• https://bugzilla.mozilla.org/show_bug.cgi?id=1659155Issue Tracking, Permissions Required, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-48/Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1659155Issue Tracking, Permissions Required, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-48/Vendor Advisory

Published

Dec 8, 2021

Last Modified

Jun 17, 2026

Status

Modified

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