CVE-2021-43531

MEDIUM
4.3
CVSS Score
Published: December 8, 2021 at 09:20 PM UTC
Updated: June 17, 2026 at 04:11 AM UTC
1 product affected across 1 vendorFirefox

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Severity
MEDIUM4.3
Exploit prediction
EPSS 0.3%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 94
Affected range stops below 94, so it looks safe — our inference, not a vendor statement
Affected range stops below 94.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

x_refsource_MISCIssue TrackingPermissions RequiredVendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1659155

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-346

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