Out-of-bounds write in Mozilla Thunderbird
Priority MEDIUM 42CWE-787Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- 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 reported memory safety bugs present in Firefox 72 and Firefox ESR 68.4. 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. In general, these flaws cannot be exploited through email in the Thunderbird product because scripting is disabled when reading mail, but are potentially risks in browser or browser-like contexts. This vulnerability affects Thunderbird < 68.5, Firefox < 73, and Firefox < ESR68.5.
Why it matters now
EPSS 0.02263 83rd percentileScored 2026-11-07
Fix Partial Thunderbird (Mozilla): 68.5Firefox (Mozilla): 73, ESR68.5Red 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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mozilla | Thunderbird | before 68.5 | 68.5 | Patch available | CNA |
| Mozilla | Firefox | before 73; before ESR68.5 | 73, ESR68.5 | Patch available | CNA |
- Thunderbird VendorMozilla Affected before 68.5 Fixed in 68.5 Patch available CNA
- Firefox VendorMozilla Affected before 73; before ESR68.5 Fixed in 73, ESR68.5 Patch available CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* | before 73.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* | before 68.5.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* | before 68.5.0 | Vulnerable | Mozilla |
| cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* | 16.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* | 18.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:* | 19.10 | Vulnerable | Canonical |
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 73.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* Versions before 68.5.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 68.5.0 Vulnerable ·Mozilla
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* Versions 16.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* Versions 18.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:* Versions 19.10 Vulnerable ·Canonical
Remediation
- Fix · CNA Thunderbird (Mozilla) Fixed in 68.5
- Fix · CNA Firefox (Mozilla) Fixed in 73, ESR68.5
Red Hat 8 advisories
- RHSA-2020:0576 Released 2020-02-24 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux Client (v. 7) thunderbird-68.5.0-1.el7_7
- Red Hat Enterprise Linux Server Optional (v. 7) thunderbird-68.5.0-1.el7_7
- Red Hat Enterprise Linux Workstation (v. 7) thunderbird-68.5.0-1.el7_7
- RHSA-2020:0574 Released 2020-02-24 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux Desktop (v. 6) thunderbird-68.5.0-1.el6_10
- Red Hat Enterprise Linux Server Optional (v. 6) thunderbird-68.5.0-1.el6_10
- Red Hat Enterprise Linux Workstation (v. 6) thunderbird-68.5.0-1.el6_10
- RHSA-2020:0577 Released 2020-02-24 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 8) thunderbird-68.5.0-1.el8_1
Show 5 more Red Hat advisories
- RHSA-2020:0565 Released 2020-02-20 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream E4S (v. 8.0) thunderbird-68.5.0-1.el8_0
- RHSA-2020:0519 Released 2020-02-18 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream E4S (v. 8.0) firefox-68.5.0-2.el8_0
- RHSA-2020:0520 Released 2020-02-18 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux Client (v. 7) firefox-68.5.0-2.el7_7
- Red Hat Enterprise Linux Client Optional (v. 7) firefox-68.5.0-2.el7_7
- Red Hat Enterprise Linux Server (v. 7) firefox-68.5.0-2.el7_7
- Red Hat Enterprise Linux Server Optional (v. 7) firefox-68.5.0-2.el7_7
- Red Hat Enterprise Linux Workstation (v. 7) firefox-68.5.0-2.el7_7
- Red Hat Enterprise Linux Workstation Optional (v. 7) firefox-68.5.0-2.el7_7
- RHSA-2020:0521 Released 2020-02-18 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux Desktop (v. 6) firefox-68.5.0-2.el6_10
- Red Hat Enterprise Linux Desktop Optional (v. 6) firefox-68.5.0-2.el6_10
- Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox-68.5.0-2.el6_10
- Red Hat Enterprise Linux Server (v. 6) firefox-68.5.0-2.el6_10
- Red Hat Enterprise Linux Server Optional (v. 6) firefox-68.5.0-2.el6_10
- Red Hat Enterprise Linux Workstation (v. 6) firefox-68.5.0-2.el6_10
- Red Hat Enterprise Linux Workstation Optional (v. 6) firefox-68.5.0-2.el6_10
- RHSA-2020:0512 Released 2020-02-17 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream (v. 8) firefox-68.5.0-2.el8_1
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Mozilla Firefox, Thunderbird — USN-4278-2
4 records Highest priority Priority MEDIUM 3 MEDIUM, 1 LOW
Other records, highest priority first
- TI-2020-05511 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 41
- TI-2020-05506 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 41
- TI-2020-05508 Cross-site scripting in Mozilla ThunderbirdPriority LOW 31
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2020:0512, RHSA-2020:0577 |
| Red Hat Enterprise Linux AppStream E4S (v. 8.0) | Fixed | RHSA-2020:0519, RHSA-2020:0565 |
| Red Hat Enterprise Linux Client (v. 7) | Fixed | RHSA-2020:0520, RHSA-2020:0576 |
| Red Hat Enterprise Linux Client Optional (v. 7) | Fixed | RHSA-2020:0520 |
| Red Hat Enterprise Linux Desktop (v. 6) | Fixed | RHSA-2020:0521, RHSA-2020:0574 |
| Red Hat Enterprise Linux Desktop Optional (v. 6) | Fixed | RHSA-2020:0521 |
| Red Hat Enterprise Linux HPC Node Optional (v. 6) | Fixed | RHSA-2020:0521 |
| Red Hat Enterprise Linux Server (v. 6) | Fixed | RHSA-2020:0521 |
| Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2020:0520 |
| Red Hat Enterprise Linux Server Optional (v. 6) | Fixed | RHSA-2020:0521, RHSA-2020:0574 |
| Red Hat Enterprise Linux Server Optional (v. 7) | Fixed | RHSA-2020:0520, RHSA-2020:0576 |
| Red Hat Enterprise Linux Workstation (v. 6) | Fixed | RHSA-2020:0521, RHSA-2020:0574 |
| Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2020:0520, RHSA-2020:0576 |
| Red Hat Enterprise Linux Workstation Optional (v. 6) | Fixed | RHSA-2020:0521 |
| Red Hat Enterprise Linux Workstation Optional (v. 7) | Fixed | RHSA-2020:0520 |
Timeline
- 2026-10-02 Threatist record created from CVE-2020-6800
- 2026-10-03 Alias added: GHSA-qjg6-3pj8-cqgj
References
Advisory 8
More Mozilla Firefox vulnerabilities
- 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
Sources
- CVE-2020-6800 · CVE Program
- CVE-2020-6800 · NVD
- FIRST EPSS
- GHSA-qjg6-3pj8-cqgj · GitHub Advisory Database · CC BY 4.0
- CVE-2020-6800 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences