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TI-2021-10604 Aliases CVE-2021-29987GHSA-h5xx-jcpx-5hr9

Missing brute-force protection in Mozilla Firefox

Priority LOW 31CWE-307Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-307.

Summary

After requesting multiple permissions, and closing the first permission panel, subsequent permission panels will be displayed in a different position but still record a click in the default location, making it possible to trick a user into accepting a permission they did not want to. *This bug only affects Firefox on Linux. Other operating systems are unaffected.*. This vulnerability affects Firefox < 91 and Thunderbird < 91.

Why it matters now

EPSS 0.00945 61st percentileScored 2026-11-07
Fix Fixed Firefox (Mozilla): 91Thunderbird (Mozilla): 91

SSVC decision points

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

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaFirefoxbefore 9191Patch availableCNA
MozillaThunderbirdbefore 9191Patch availableCNA
  • Firefox VendorMozilla Affected before 91 Fixed in 91 Patch available CNA
  • Thunderbird VendorMozilla Affected before 91 Fixed in 91 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*before 91.0VulnerableMozilla
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*before 91.0VulnerableMozilla
cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*not specified by NVDRunning onLinux
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 91.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 91.0 Vulnerable ·Mozilla
  • cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Linux

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 91
  • Fix · CNA Thunderbird (Mozilla) Fixed in 91

Fixed in the same release

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

  • Release ·

    Mozilla Firefox 91

    11 records Highest priority Priority MEDIUM 7 MEDIUM, 4 LOW

    Other records, highest priority first

    • TI-2021-10606 Out-of-bounds write in Mozilla ThunderbirdPriority MEDIUM 41
    • TI-2021-10605 Out-of-bounds read in Mozilla ThunderbirdPriority MEDIUM 41
    • TI-2021-10602 Use after free in Mozilla ThunderbirdPriority MEDIUM 41
    Show all 11 records →
  • Release ·

    Mozilla Thunderbird 91

    3 records Highest priority Priority MEDIUM 1 MEDIUM, 2 LOW

    Other records, highest priority first

    • TI-2021-10598 An issue present in lowering/register allocation could have led to obscure but…Priority MEDIUM 40
    • TI-2021-10599 Due to incorrect JIT optimization, we incorrectly interpreted data from the wrong type of…Priority LOW 31
    Show all 3 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-29987
  2. 2026-10-03 Alias added: GHSA-h5xx-jcpx-5hr9

References

Advisory 4

  • 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