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TI-2021-19421 Aliases CVE-2021-43531GHSA-r6p5-8pxg-2vcp

Origin validation error in Mozilla Firefox

Priority LOW 20CWE-346Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
Low · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-346.

Summary

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.

Why it matters now

EPSS 0.0034 27th percentileScored 2026-11-08
Fix Fixed Firefox (Mozilla): 94

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaFirefoxbefore 9494Patch availableCNA
  • Firefox VendorMozilla Affected before 94 Fixed in 94 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*before 94.0VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 94.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 94

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Mozilla Firefox 94

    6 records Highest priority Priority MEDIUM 1 MEDIUM, 5 LOW

    Other records, highest priority first

    • TI-2021-16110 The executable file warning was not presented when downloading .inetloc files, which, due…Priority MEDIUM 40
    • TI-2021-16105 Exposure of resource to wrong sphere in Mozilla FirefoxPriority LOW 31
    • TI-2021-19420 Cross-site scripting in Mozilla FirefoxPriority LOW 30
    Show all 6 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-43531
  2. 2026-10-03 Alias added: GHSA-r6p5-8pxg-2vcp

References

Advisory 2

  • TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
  • TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
  • TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
  • TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
  • TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
  • TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
See all 3444 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences