Out-of-bounds write in Mozilla Firefox ESR
Priority MEDIUM 51CWE-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: 20 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
A buffer overflow could occur when parsing and validating SCTP chunks in WebRTC. This could have led to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox ESR < 68.8, Firefox < 76, and Thunderbird < 68.8.0.
Why it matters now
EPSS 0.05803 93rd percentileScored 2026-11-07
Fix Partial Firefox ESR (Mozilla): 68.8Firefox (Mozilla): 76+1 more productRed Hat: 11 advisoriesRed Hat: 20 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 | Firefox ESR | before 68.8 | 68.8 | Patch available | CNA |
| Mozilla | Firefox | before 76 | 76 | Patch available | CNA |
| Mozilla | Thunderbird | before 68.8.0 | 68.8.0 | Patch available | CNA |
- Firefox ESR VendorMozilla Affected before 68.8 Fixed in 68.8 Patch available CNA
- Firefox VendorMozilla Affected before 76 Fixed in 76 Patch available CNA
- Thunderbird VendorMozilla Affected before 68.8.0 Fixed in 68.8.0 Patch available CNA
CPE configurations NVD · 10
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* | before 76.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* | before 68.8.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* | before 68.8.0 | Vulnerable | Mozilla |
| cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* | 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:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:* | 20.04 | Vulnerable | Canonical |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Debian |
| cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:* | 15.2 | Vulnerable | openSUSE |
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 76.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* Versions before 68.8.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 68.8.0 Vulnerable ·Mozilla
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* 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
- cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:* Versions 20.04 Vulnerable ·Canonical
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
- cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:* Versions 15.2 Vulnerable ·openSUSE
Remediation
- Fix · CNA Firefox ESR (Mozilla) Fixed in 68.8
- Fix · CNA Firefox (Mozilla) Fixed in 76
- Fix · CNA Thunderbird (Mozilla) Fixed in 68.8.0
Red Hat 11 advisories
- RHSA-2020:2064 Released 2020-05-11 · Red Hat rating Importantchromium-browser security update
- Red Hat Enterprise Linux Desktop Supplementary (v. 6) chromium-browser-81.0.4044.138-1.el6_10
- Red Hat Enterprise Linux HPC Node Supplementary (v. 6) chromium-browser-81.0.4044.138-1.el6_10
- Red Hat Enterprise Linux Server Supplementary (v. 6) chromium-browser-81.0.4044.138-1.el6_10
- Red Hat Enterprise Linux Workstation Supplementary (v. 6) chromium-browser-81.0.4044.138-1.el6_10
- RHSA-2020:2050 Released 2020-05-11 · Red Hat rating Criticalthunderbird security update
- Red Hat Enterprise Linux Client (v. 7) thunderbird-68.8.0-1.el7_8
- Red Hat Enterprise Linux Server Optional (v. 7) thunderbird-68.8.0-1.el7_8
- Red Hat Enterprise Linux Workstation (v. 7) thunderbird-68.8.0-1.el7_8
- RHSA-2020:2049 Released 2020-05-11 · Red Hat rating Criticalthunderbird security update
- Red Hat Enterprise Linux Desktop (v. 6) thunderbird-68.8.0-1.el6_10
- Red Hat Enterprise Linux Server Optional (v. 6) thunderbird-68.8.0-1.el6_10
- Red Hat Enterprise Linux Workstation (v. 6) thunderbird-68.8.0-1.el6_10
Show 8 more Red Hat advisories
- RHSA-2020:2046 Released 2020-05-11 · Red Hat rating Criticalthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 8) thunderbird-68.8.0-1.el8_2
- RHSA-2020:2047 Released 2020-05-11 · Red Hat rating Criticalthunderbird security update
- Red Hat Enterprise Linux AppStream EUS (v. 8.1) thunderbird-68.8.0-1.el8_1
- RHSA-2020:2048 Released 2020-05-11 · Red Hat rating Criticalthunderbird security update
- Red Hat Enterprise Linux AppStream E4S (v. 8.0) thunderbird-68.8.0-1.el8_0
- RHSA-2020:2036 Released 2020-05-06 · Red Hat rating Criticalfirefox security update
- Red Hat Enterprise Linux Desktop (v. 6) firefox-68.8.0-1.el6_10
- Red Hat Enterprise Linux Desktop Optional (v. 6) firefox-68.8.0-1.el6_10
- Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox-68.8.0-1.el6_10
- Red Hat Enterprise Linux Server (v. 6) firefox-68.8.0-1.el6_10
- Red Hat Enterprise Linux Server Optional (v. 6) firefox-68.8.0-1.el6_10
- Red Hat Enterprise Linux Workstation (v. 6) firefox-68.8.0-1.el6_10
- Red Hat Enterprise Linux Workstation Optional (v. 6) firefox-68.8.0-1.el6_10
- RHSA-2020:2037 Released 2020-05-06 · Red Hat rating Criticalfirefox security update
- Red Hat Enterprise Linux Client (v. 7) firefox-68.8.0-1.el7_8
- Red Hat Enterprise Linux Client Optional (v. 7) firefox-68.8.0-1.el7_8
- Red Hat Enterprise Linux Server (v. 7) firefox-68.8.0-1.el7_8
- Red Hat Enterprise Linux Server Optional (v. 7) firefox-68.8.0-1.el7_8
- Red Hat Enterprise Linux Workstation (v. 7) firefox-68.8.0-1.el7_8
- Red Hat Enterprise Linux Workstation Optional (v. 7) firefox-68.8.0-1.el7_8
- RHSA-2020:2031 Released 2020-05-06 · Red Hat rating Criticalfirefox security update
- Red Hat Enterprise Linux AppStream (v. 8) firefox-68.8.0-1.el8_2
- RHSA-2020:2032 Released 2020-05-06 · Red Hat rating Criticalfirefox security update
- Red Hat Enterprise Linux AppStream EUS (v. 8.1) firefox-68.8.0-1.el8_1
- RHSA-2020:2033 Released 2020-05-06 · Red Hat rating Criticalfirefox security update
- Red Hat Enterprise Linux AppStream E4S (v. 8.0) firefox-68.8.0-1.el8_0
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Mozilla Firefox, Firefox ESR, Thunderbird — USN-4373-1
5 records Highest priority Priority MEDIUM 2 MEDIUM, 3 LOW
Other records, highest priority first
- TI-2020-09913 Out-of-bounds write in Mozilla Firefox ESRPriority MEDIUM 47
- TI-2020-09905 Race condition in Mozilla Firefox ESRPriority LOW 38
- TI-2020-09910 Path traversal in Mozilla Firefox ESRPriority LOW 25
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-2020:2031, RHSA-2020:2046 |
| Red Hat Enterprise Linux AppStream E4S (v. 8.0) | Fixed | RHSA-2020:2033, RHSA-2020:2048 |
| Red Hat Enterprise Linux AppStream EUS (v. 8.1) | Fixed | RHSA-2020:2032, RHSA-2020:2047 |
| Red Hat Enterprise Linux Client (v. 7) | Fixed | RHSA-2020:2037, RHSA-2020:2050 |
| Red Hat Enterprise Linux Client Optional (v. 7) | Fixed | RHSA-2020:2037 |
| Red Hat Enterprise Linux Desktop (v. 6) | Fixed | RHSA-2020:2036, RHSA-2020:2049 |
| Red Hat Enterprise Linux Desktop Optional (v. 6) | Fixed | RHSA-2020:2036 |
| Red Hat Enterprise Linux Desktop Supplementary (v. 6) | Fixed | RHSA-2020:2064 |
| Red Hat Enterprise Linux HPC Node Optional (v. 6) | Fixed | RHSA-2020:2036 |
| Red Hat Enterprise Linux HPC Node Supplementary (v. 6) | Fixed | RHSA-2020:2064 |
| Red Hat Enterprise Linux Server (v. 6) | Fixed | RHSA-2020:2036 |
| Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2020:2037 |
| Red Hat Enterprise Linux Server Optional (v. 6) | Fixed | RHSA-2020:2036, RHSA-2020:2049 |
| Red Hat Enterprise Linux Server Optional (v. 7) | Fixed | RHSA-2020:2037, RHSA-2020:2050 |
| Red Hat Enterprise Linux Server Supplementary (v. 6) | Fixed | RHSA-2020:2064 |
| Red Hat Enterprise Linux Workstation (v. 6) | Fixed | RHSA-2020:2036, RHSA-2020:2049 |
| Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2020:2037, RHSA-2020:2050 |
| Red Hat Enterprise Linux Workstation Optional (v. 6) | Fixed | RHSA-2020:2036 |
| Red Hat Enterprise Linux Workstation Optional (v. 7) | Fixed | RHSA-2020:2037 |
| Red Hat Enterprise Linux Workstation Supplementary (v. 6) | Fixed | RHSA-2020:2064 |
Timeline
- 2026-10-02 Threatist record created from CVE-2020-6831
- 2026-10-03 Alias added: GHSA-5x26-44w7-97vc
References
Advisory 8
- https://www.mozilla.org/security/advisories/mfsa2020-18/
- https://www.mozilla.org/security/advisories/mfsa2020-16/
- https://www.mozilla.org/security/advisories/mfsa2020-17/
- USN-4373-1
- https://security.gentoo.org/glsa/202005-04
- DSA-4714
- openSUSE-SU-2020:0917
- http://packetstormsecurity.com/files/158480/usrsctp-Stack-Buffer-Overflow.html
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-2020-6831 · CVE Program
- CVE-2020-6831 · NVD
- FIRST EPSS
- GHSA-5x26-44w7-97vc · GitHub Advisory Database · CC BY 4.0
- CVE-2020-6831 · 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