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high 8.8

CVE-2020-6822 json

On 32-bit builds, an out of bounds write could have occurred when processing an image larger than 4 GB in <code>GMPDecodeData</code>. It is…

published 6y ago modified 4mo ago also EUVD-2020-27966

cvss
8.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 71%
public exploits
0
none known

Summary

On 32-bit builds, an out of bounds write could have occurred when processing an image larger than 4 GB in <code>GMPDecodeData</code>. It is possible that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 68.7.0, Firefox ESR < 68.7, and Firefox < 75.

Patch / fix

  • Mozilla Thunderbird 68.7.0
  • Mozilla Firefox ESR 68.7
  • Mozilla Firefox 75
  • firefox-esr Debian 14, Debian 13, Debian 12 68.7.0esr-1
  • thunderbird Debian 14, Debian 13, Debian 12 1:68.7.0-1

debian advisories DEBIAN-CVE-2020-6822

  • firefox Ubuntu 16.04 LTS 75.0+build3-0ubuntu0.16.04.1
  • firefox Ubuntu 18.04 LTS 75.0+build3-0ubuntu0.18.04.1
  • firefox Ubuntu 20.04 LTS 75.0+build3-0ubuntu1
  • thunderbird Ubuntu 16.04 LTS 1:68.7.0+build1-0ubuntu0.16.04.2
  • thunderbird Ubuntu 18.04 LTS 1:68.7.0+build1-0ubuntu0.18.04.1
  • thunderbird Ubuntu 20.04 LTS 1:68.7.0+build1-0ubuntu1

ubuntu advisories UBUNTU-CVE-2020-6822

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • thunderbird RHEL 8 68.7.0-1.el8_1
  • thunderbird RHEL 7 68.7.0-1.el7_8
  • thunderbird RHEL 6 68.7.0-1.el6_10
  • firefox RHEL 6 68.7.0-2.el6_10
  • firefox RHEL 7 68.7.0-2.el7_8
  • firefox RHEL 8 68.7.0-2.el8_1
  • thunderbird RHEL 8.0 E4S 68.7.0-1.el8_0
  • firefox RHEL 8.0 E4S 68.7.0-2.el8_0

red hat advisories RHSA-2020:1495RHSA-2020:1496RHSA-2020:1489RHSA-2020:1488RHSA-2020:1429RHSA-2020:1420

  • MozillaThunderbird SLE Workstation Extension 15 SP1 68.7.0-3.77.1
  • MozillaFirefox SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +16 more 68.7.0-109.116.1
  • MozillaFirefox SLE Module for Desktop Applications 15 SP1 68.7.0-3.84.2
  • MozillaFirefox SLES 11 SP4-LTSS 68.7.0-78.70.1

suse advisories SUSE-SU-2020:1027-1SUSE-SU-2020:0978-1SUSE-SU-2020:14339-1SUSE-SU-2020:0971-1

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 92.0-1.2
  • MozillaThunderbird openSUSE Tumbleweed 91.1.1-1.1
  • MozillaThunderbird openSUSE Leap 15.1 68.7.0-lp151.2.35.1
  • MozillaThunderbird openSUSE Leap 15.1 68.7.0-lp151.2.31.1
  • MozillaFirefox openSUSE Leap 15.1 68.7.0-lp151.2.42.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10600-1openSUSE-SU-2024:10601-1openSUSE-SU-2020:0544-1openSUSE-SU-2020:0520-1openSUSE-SU-2020:0493-1

  • firefox Alpine 3.23, Alpine 3.22, Alpine 3.21 +9 more 75.0-r0
  • mozjs68 Alpine 3.12 68.7.0-r0
  • librewolf Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 75.0-r0
  • firefox-esr Alpine 3.23, Alpine 3.22, Alpine 3.21 +10 more 68.7.0-r0
  • thunderbird Alpine 3.23, Alpine 3.22, Alpine 3.21 +5 more 68.7.0-r0

alpine advisories ALPINE-CVE-2020-6822

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Is CVE-2020-6822 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-6822 updated cvss 8.8

Mozilla: Out of bounds write in GMPDecodeData when processing large images

  • Red Hat Enterprise Linux 5 firefox, thunderbird
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) firefox 68.7.0-2.el8_1, thunderbird 68.7.0-1.el8_1
    fixed: vendor fix RHSA-2020:1406
  • Red Hat Enterprise Linux AppStream E4S (v. 8.0) firefox 68.7.0-2.el8_0, thunderbird 68.7.0-1.el8_0
    fixed: vendor fix RHSA-2020:1404
  • Red Hat Enterprise Linux Client (v. 7) firefox 68.7.0-2.el7_8, thunderbird 68.7.0-1.el7_8 Red Hat Enterprise Linux Client Optional (v. 7) firefox 68.7.0-2.el7_8
    fixed: vendor fix RHSA-2020:1420
  • Red Hat Enterprise Linux Desktop (v. 6) firefox 68.7.0-2.el6_10, thunderbird 68.7.0-1.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
    fixed: vendor fix RHSA-2020:1429
  • Red Hat Enterprise Linux Server (v. 7) firefox 68.7.0-2.el7_8
    fixed: vendor fix RHSA-2020:1420
  • Red Hat Enterprise Linux Server Optional (v. 6) firefox 68.7.0-2.el6_10, thunderbird 68.7.0-1.el6_10
    fixed: vendor fix RHSA-2020:1429
  • Red Hat Enterprise Linux Server Optional (v. 7) firefox 68.7.0-2.el7_8, thunderbird 68.7.0-1.el7_8
    fixed: vendor fix RHSA-2020:1420
show 4 more
  • Red Hat Enterprise Linux Workstation (v. 6) firefox 68.7.0-2.el6_10, thunderbird 68.7.0-1.el6_10
    fixed: vendor fix RHSA-2020:1429
  • Red Hat Enterprise Linux Workstation (v. 7) firefox 68.7.0-2.el7_8, thunderbird 68.7.0-1.el7_8
    fixed: vendor fix RHSA-2020:1420
  • Red Hat Enterprise Linux Workstation Optional (v. 6) firefox 68.7.0-2.el6_10
    fixed: vendor fix RHSA-2020:1429
  • Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 68.7.0-2.el7_8
    fixed: vendor fix RHSA-2020:1420

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.33% chance of exploitation in the next 30 days, higher than 71% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • Mozilla Thunderbird
  • Mozilla Firefox ESR
  • Mozilla Firefox

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.