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TI-2020-05534 Aliases CVE-2020-6825GHSA-pj8r-w3xr-j4w5

Out-of-bounds write in Mozilla Thunderbird

Priority MEDIUM 46CWE-787Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 15 fixed, 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.

Summary

Mozilla developers and community members Tyson Smith and Christian Holler reported memory safety bugs present in Firefox 74 and Firefox ESR 68.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 68.7.0, Firefox ESR < 68.7, and Firefox < 75.

Why it matters now

EPSS 0.02188 82nd percentileScored 2026-11-07
Fix Partial Thunderbird (Mozilla): 68.7.0Firefox ESR (Mozilla): 68.7+1 more productRed Hat: 8 advisoriesRed Hat: 15 fixed, 1 without a fix

SSVC decision points

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

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaThunderbirdbefore 68.7.068.7.0Patch availableCNA
MozillaFirefox ESRbefore 68.768.7Patch availableCNA
MozillaFirefoxbefore 7575Patch availableCNA
  • Thunderbird VendorMozilla Affected before 68.7.0 Fixed in 68.7.0 Patch available CNA
  • Firefox ESR VendorMozilla Affected before 68.7 Fixed in 68.7 Patch available CNA
  • Firefox VendorMozilla Affected before 75 Fixed in 75 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*before 75.0VulnerableMozilla
cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*before 68.7.0VulnerableMozilla
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*before 68.7.0VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 75.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* Versions before 68.7.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 68.7.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Thunderbird (Mozilla) Fixed in 68.7.0
  • Fix · CNA Firefox ESR (Mozilla) Fixed in 68.7
  • Fix · CNA Firefox (Mozilla) Fixed in 75

Red Hat 8 advisories

  • RHSA-2020:1495 Released 2020-04-16 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 8) thunderbird-68.7.0-1.el8_1
  • RHSA-2020:1496 Released 2020-04-16 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v. 8.0) thunderbird-68.7.0-1.el8_0
  • RHSA-2020:1488 Released 2020-04-16 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux Desktop (v. 6) thunderbird-68.7.0-1.el6_10
    • Red Hat Enterprise Linux Server Optional (v. 6) thunderbird-68.7.0-1.el6_10
    • Red Hat Enterprise Linux Workstation (v. 6) thunderbird-68.7.0-1.el6_10
Show 5 more Red Hat advisories
  • RHSA-2020:1489 Released 2020-04-16 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux Client (v. 7) thunderbird-68.7.0-1.el7_8
    • Red Hat Enterprise Linux Server Optional (v. 7) thunderbird-68.7.0-1.el7_8
    • Red Hat Enterprise Linux Workstation (v. 7) thunderbird-68.7.0-1.el7_8
  • RHSA-2020:1429 Released 2020-04-14 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux Desktop (v. 6) firefox-68.7.0-2.el6_10
    • Red Hat Enterprise Linux Desktop Optional (v. 6) firefox-68.7.0-2.el6_10
    • Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox-68.7.0-2.el6_10
    • Red Hat Enterprise Linux Server (v. 6) firefox-68.7.0-2.el6_10
    • Red Hat Enterprise Linux Server Optional (v. 6) firefox-68.7.0-2.el6_10
    • Red Hat Enterprise Linux Workstation (v. 6) firefox-68.7.0-2.el6_10
    • Red Hat Enterprise Linux Workstation Optional (v. 6) firefox-68.7.0-2.el6_10
  • RHSA-2020:1420 Released 2020-04-09 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux Client (v. 7) firefox-68.7.0-2.el7_8
    • Red Hat Enterprise Linux Client Optional (v. 7) firefox-68.7.0-2.el7_8
    • Red Hat Enterprise Linux Server (v. 7) firefox-68.7.0-2.el7_8
    • Red Hat Enterprise Linux Server Optional (v. 7) firefox-68.7.0-2.el7_8
    • Red Hat Enterprise Linux Workstation (v. 7) firefox-68.7.0-2.el7_8
    • Red Hat Enterprise Linux Workstation Optional (v. 7) firefox-68.7.0-2.el7_8
  • RHSA-2020:1406 Released 2020-04-08 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 8) firefox-68.7.0-2.el8_1
  • RHSA-2020:1404 Released 2020-04-08 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v. 8.0) firefox-68.7.0-2.el8_0

Fixed in the same release

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

  • Release ·

    Mozilla Firefox 75

    6 records Highest priority Priority MEDIUM 4 MEDIUM, 2 LOW

    Other records, highest priority first

    • TI-2020-05535 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 45
    • TI-2020-05532 Missing authorization in Mozilla FirefoxPriority MEDIUM 45
    • TI-2020-05531 Out-of-bounds write in Mozilla ThunderbirdPriority MEDIUM 41
    Show all 6 records →
  • Release ·

    Mozilla Firefox ESR 68.7

    5 records Highest priority Priority MEDIUM 2 MEDIUM, 3 LOW

    Other records, highest priority first

    • TI-2020-05531 Out-of-bounds write in Mozilla ThunderbirdPriority MEDIUM 41
    • TI-2020-05537 Path traversal in Mozilla Firefox ESRPriority LOW 36
    • TI-2020-05530 Use of uninitialized resource in Mozilla ThunderbirdPriority LOW 36
    Show all 5 records →
Show 1 more group
  • Release ·

    Mozilla Thunderbird 68.7.0

    5 records Highest priority Priority CRITICAL 2 CRITICAL, 2 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2020-05529 Race condition in Mozilla ThunderbirdPriority CRITICAL 94
    • TI-2020-05528 Use after free in Mozilla ThunderbirdPriority CRITICAL 94
    • TI-2020-05531 Out-of-bounds write in Mozilla ThunderbirdPriority MEDIUM 41
    Show all 5 records →

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 5AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2020:1406, RHSA-2020:1495
Red Hat Enterprise Linux AppStream E4S (v. 8.0)Fixed RHSA-2020:1404, RHSA-2020:1496
Red Hat Enterprise Linux Client (v. 7)Fixed RHSA-2020:1420, RHSA-2020:1489
Red Hat Enterprise Linux Client Optional (v. 7)Fixed RHSA-2020:1420
Red Hat Enterprise Linux Desktop (v. 6)Fixed RHSA-2020:1429, RHSA-2020:1488
Red Hat Enterprise Linux Desktop Optional (v. 6)Fixed RHSA-2020:1429
Red Hat Enterprise Linux HPC Node Optional (v. 6)Fixed RHSA-2020:1429
Red Hat Enterprise Linux Server (v. 6)Fixed RHSA-2020:1429
Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2020:1420
Red Hat Enterprise Linux Server Optional (v. 6)Fixed RHSA-2020:1429, RHSA-2020:1488
Red Hat Enterprise Linux Server Optional (v. 7)Fixed RHSA-2020:1420, RHSA-2020:1489
Red Hat Enterprise Linux Workstation (v. 6)Fixed RHSA-2020:1429, RHSA-2020:1488
Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2020:1420, RHSA-2020:1489
Red Hat Enterprise Linux Workstation Optional (v. 6)Fixed RHSA-2020:1429
Red Hat Enterprise Linux Workstation Optional (v. 7)Fixed RHSA-2020:1420

Timeline

  1. 2026-10-02 Threatist record created from CVE-2020-6825
  2. 2026-10-03 Alias added: GHSA-pj8r-w3xr-j4w5

References

Advisory 4

Other 1

  • 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