CVE-2020-6820

Under certain conditions, when handling a ReadableStream, a race condition can cause a use-after-free. We are aware of targeted attacks in the wild abusing this flaw. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1.
Race Condition
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
8.1 HIGH
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 87%
Affected Products (NVD)
VendorProductVersion
mozillafirefox_esr
𝑥
< 68.6.1
mozillafirefox
𝑥
< 74.0.1
mozillathunderbird
𝑥
< 68.7.0
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
firefox
sid
132.0.1-1
fixed
firefox-esr
bookworm
115.14.0esr-1~deb12u1
fixed
bookworm (security)
128.4.0esr-1~deb12u1
fixed
bullseye
115.14.0esr-1~deb11u1
fixed
bullseye (security)
128.4.0esr-1~deb11u1
fixed
sid
128.4.0esr-1
fixed
trixie
128.3.1esr-2
fixed
thunderbird
bookworm
1:115.12.0-1~deb12u1
fixed
bookworm (security)
1:128.4.0esr-1~deb12u1
fixed
bullseye
1:115.12.0-1~deb11u1
fixed
bullseye (security)
1:128.4.0esr-1~deb11u1
fixed
sid
1:128.4.0esr-1
fixed
trixie
1:128.4.0esr-1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
firefox
bionic
Fixed 74.0.1+build1-0ubuntu0.18.04.1
released
eoan
Fixed 74.0.1+build1-0ubuntu0.19.10.1
released
focal
Fixed 75.0+build3-0ubuntu1
released
trusty
dne
xenial
Fixed 74.0.1+build1-0ubuntu0.16.04.1
released
thunderbird
bionic
Fixed 1:68.7.0+build1-0ubuntu0.18.04.1
released
eoan
Fixed 1:68.7.0+build1-0ubuntu0.19.10.1
released
focal
Fixed 1:68.7.0+build1-0ubuntu1
released
trusty
dne
xenial
Fixed 1:68.7.0+build1-0ubuntu0.16.04.2
released
openSUSE logo
openSUSE / SLES Releases
openSUSE Product
Release
MozillaFirefox
suse enterprise desktop 15 SP1
68.6.1-3.81.1
fixed
suse enterprise desktop 15 SP2
68.6.1-3.81.1
fixed
suse enterprise desktop 15 SP3
78.10.0-8.38.1
fixed
suse enterprise desktop 15 SP4
91.8.0-150200.152.26.1
fixed
suse enterprise desktop 15 SP5
102.11.0-150200.152.87.1
fixed
suse enterprise desktop 15 SP6
115.10.0-150200.152.134.1
fixed
suse enterprise desktop 15 SP7
128.9.0-150200.152.176.1
fixed
suse enterprise sap 12 SP1
68.6.1-109.113.1
fixed
suse enterprise sap 12 SP4
68.6.1-109.113.1
fixed
suse enterprise sap 12 SP5
68.6.1-109.113.1
fixed
suse enterprise sap 15 SP1
68.6.1-3.81.1
fixed
suse enterprise sap 15 SP2
68.6.1-3.81.1
fixed
suse enterprise sap 15 SP3
78.10.0-8.38.1
fixed
suse enterprise sap 15 SP4
91.8.0-150200.152.26.1
fixed
suse enterprise sap 15 SP5
102.11.0-150200.152.87.1
fixed
suse enterprise sap 15 SP6
115.10.0-150200.152.134.1
fixed
suse enterprise sap 15 SP7
128.9.0-150200.152.176.1
fixed
suse enterprise server 12 SP1
68.6.1-109.113.1
fixed
suse enterprise server 12 SP2
68.6.1-109.113.1
fixed
suse enterprise server 12 SP3
68.6.1-109.113.1
fixed
suse enterprise server 12 SP4
68.6.1-109.113.1
fixed
suse enterprise server 12 SP5
68.6.1-109.113.1
fixed
suse enterprise server 15 SP1
68.6.1-3.81.1
fixed
suse enterprise server 15 SP2
68.6.1-3.81.1
fixed
suse enterprise server 15 SP3
78.10.0-8.38.1
fixed
suse enterprise server 15 SP4
91.8.0-150200.152.26.1
fixed
suse enterprise server 15 SP5
102.11.0-150200.152.87.1
fixed
suse enterprise server 15 SP6
115.10.0-150200.152.134.1
fixed
suse enterprise server 15 SP7
128.9.0-150200.152.176.1
fixed
MozillaFirefox-devel
suse enterprise desktop 15 SP1
68.6.1-3.81.1
fixed
suse enterprise desktop 15 SP2
68.6.1-3.81.1
fixed
suse enterprise desktop 15 SP3
78.10.0-8.38.1
fixed
suse enterprise desktop 15 SP4
91.8.0-150200.152.26.1
fixed
suse enterprise desktop 15 SP5
102.11.0-150200.152.87.1
fixed
suse enterprise desktop 15 SP6
102.12.0-150200.152.90.1
fixed
suse enterprise desktop 15 SP7
102.12.0-150200.152.90.1
fixed
suse enterprise sap 12 SP1
68.6.1-109.113.1
fixed
suse enterprise sap 15 SP1
68.6.1-3.81.1
fixed
suse enterprise sap 15 SP2
68.6.1-3.81.1
fixed
suse enterprise sap 15 SP3
78.10.0-8.38.1
fixed
suse enterprise sap 15 SP4
91.8.0-150200.152.26.1
fixed
suse enterprise sap 15 SP5
102.11.0-150200.152.87.1
fixed
suse enterprise sap 15 SP6
102.12.0-150200.152.90.1
fixed
suse enterprise sap 15 SP7
102.12.0-150200.152.90.1
fixed
suse enterprise server 12 SP1
68.6.1-109.113.1
fixed
suse enterprise server 12 SP2
68.6.1-109.113.1
fixed
suse enterprise server 15 SP1
68.6.1-3.81.1
fixed
suse enterprise server 15 SP2
68.6.1-3.81.1
fixed
suse enterprise server 15 SP3
78.10.0-8.38.1
fixed
suse enterprise server 15 SP4
91.8.0-150200.152.26.1
fixed
suse enterprise server 15 SP5
102.11.0-150200.152.87.1
fixed
suse enterprise server 15 SP6
102.12.0-150200.152.90.1
fixed
suse enterprise server 15 SP7
102.12.0-150200.152.90.1
fixed
MozillaFirefox-translations-common
suse enterprise desktop 15 SP1
68.6.1-3.81.1
fixed
suse enterprise desktop 15 SP2
68.6.1-3.81.1
fixed
suse enterprise desktop 15 SP3
78.10.0-8.38.1
fixed
suse enterprise desktop 15 SP4
91.8.0-150200.152.26.1
fixed
suse enterprise desktop 15 SP5
102.11.0-150200.152.87.1
fixed
suse enterprise desktop 15 SP6
115.10.0-150200.152.134.1
fixed
suse enterprise desktop 15 SP7
128.9.0-150200.152.176.1
fixed
suse enterprise sap 12 SP1
68.6.1-109.113.1
fixed
suse enterprise sap 12 SP4
68.6.1-109.113.1
fixed
suse enterprise sap 12 SP5
68.6.1-109.113.1
fixed
suse enterprise sap 15 SP1
68.6.1-3.81.1
fixed
suse enterprise sap 15 SP2
68.6.1-3.81.1
fixed
suse enterprise sap 15 SP3
78.10.0-8.38.1
fixed
suse enterprise sap 15 SP4
91.8.0-150200.152.26.1
fixed
suse enterprise sap 15 SP5
102.11.0-150200.152.87.1
fixed
suse enterprise sap 15 SP6
115.10.0-150200.152.134.1
fixed
suse enterprise sap 15 SP7
128.9.0-150200.152.176.1
fixed
suse enterprise server 12 SP1
68.6.1-109.113.1
fixed
suse enterprise server 12 SP2
68.6.1-109.113.1
fixed
suse enterprise server 12 SP3
68.6.1-109.113.1
fixed
suse enterprise server 12 SP4
68.6.1-109.113.1
fixed
suse enterprise server 12 SP5
68.6.1-109.113.1
fixed
suse enterprise server 15 SP1
68.6.1-3.81.1
fixed
suse enterprise server 15 SP2
68.6.1-3.81.1
fixed
suse enterprise server 15 SP3
78.10.0-8.38.1
fixed
suse enterprise server 15 SP4
91.8.0-150200.152.26.1
fixed
suse enterprise server 15 SP5
102.11.0-150200.152.87.1
fixed
suse enterprise server 15 SP6
115.10.0-150200.152.134.1
fixed
suse enterprise server 15 SP7
128.9.0-150200.152.176.1
fixed
MozillaFirefox-translations-other
suse enterprise desktop 15 SP1
68.6.1-3.81.1
fixed
suse enterprise desktop 15 SP2
68.6.1-3.81.1
fixed
suse enterprise desktop 15 SP3
78.10.0-8.38.1
fixed
suse enterprise desktop 15 SP4
91.8.0-150200.152.26.1
fixed
suse enterprise desktop 15 SP5
102.11.0-150200.152.87.1
fixed
suse enterprise desktop 15 SP6
115.10.0-150200.152.134.1
fixed
suse enterprise desktop 15 SP7
128.9.0-150200.152.176.1
fixed
suse enterprise sap 15 SP1
68.6.1-3.81.1
fixed
suse enterprise sap 15 SP2
68.6.1-3.81.1
fixed
suse enterprise sap 15 SP3
78.10.0-8.38.1
fixed
suse enterprise sap 15 SP4
91.8.0-150200.152.26.1
fixed
suse enterprise sap 15 SP5
102.11.0-150200.152.87.1
fixed
suse enterprise sap 15 SP6
115.10.0-150200.152.134.1
fixed
suse enterprise sap 15 SP7
128.9.0-150200.152.176.1
fixed
suse enterprise server 15 SP1
68.6.1-3.81.1
fixed
suse enterprise server 15 SP2
68.6.1-3.81.1
fixed
suse enterprise server 15 SP3
78.10.0-8.38.1
fixed
suse enterprise server 15 SP4
91.8.0-150200.152.26.1
fixed
suse enterprise server 15 SP5
102.11.0-150200.152.87.1
fixed
suse enterprise server 15 SP6
115.10.0-150200.152.134.1
fixed
suse enterprise server 15 SP7
128.9.0-150200.152.176.1
fixed
MozillaThunderbird
suse enterprise desktop 15 SP1
68.7.0-3.77.1
fixed
suse enterprise desktop 15 SP2
68.7.0-3.77.1
fixed
suse enterprise desktop 15 SP3
78.10.0-8.23.1
fixed
suse enterprise desktop 15 SP4
91.8.0-150200.8.65.1
fixed
suse enterprise sap 15 SP1
68.7.0-3.77.1
fixed
suse enterprise sap 15 SP2
68.7.0-3.77.1
fixed
suse enterprise sap 15 SP3
78.10.0-8.23.1
fixed
suse enterprise sap 15 SP4
91.8.0-150200.8.65.1
fixed
suse enterprise server 15 SP1
68.7.0-3.77.1
fixed
suse enterprise server 15 SP2
68.7.0-3.77.1
fixed
suse enterprise server 15 SP3
78.10.0-8.23.1
fixed
suse enterprise server 15 SP4
91.8.0-150200.8.65.1
fixed
suse enterprise workstation 15 SP1
68.7.0-3.77.1
fixed
suse enterprise workstation 15 SP2
68.7.0-3.77.1
fixed
suse enterprise workstation 15 SP3
78.10.0-8.23.1
fixed
suse enterprise workstation 15 SP4
91.8.0-150200.8.65.1
fixed
MozillaThunderbird-translations-common
suse enterprise desktop 15 SP1
68.7.0-3.77.1
fixed
suse enterprise desktop 15 SP2
68.7.0-3.77.1
fixed
suse enterprise desktop 15 SP3
78.10.0-8.23.1
fixed
suse enterprise desktop 15 SP4
91.8.0-150200.8.65.1
fixed
suse enterprise sap 15 SP1
68.7.0-3.77.1
fixed
suse enterprise sap 15 SP2
68.7.0-3.77.1
fixed
suse enterprise sap 15 SP3
78.10.0-8.23.1
fixed
suse enterprise sap 15 SP4
91.8.0-150200.8.65.1
fixed
suse enterprise server 15 SP1
68.7.0-3.77.1
fixed
suse enterprise server 15 SP2
68.7.0-3.77.1
fixed
suse enterprise server 15 SP3
78.10.0-8.23.1
fixed
suse enterprise server 15 SP4
91.8.0-150200.8.65.1
fixed
suse enterprise workstation 15 SP1
68.7.0-3.77.1
fixed
suse enterprise workstation 15 SP2
68.7.0-3.77.1
fixed
suse enterprise workstation 15 SP3
78.10.0-8.23.1
fixed
suse enterprise workstation 15 SP4
91.8.0-150200.8.65.1
fixed
MozillaThunderbird-translations-other
suse enterprise desktop 15 SP1
68.7.0-3.77.1
fixed
suse enterprise desktop 15 SP2
68.7.0-3.77.1
fixed
suse enterprise desktop 15 SP3
78.10.0-8.23.1
fixed
suse enterprise desktop 15 SP4
91.8.0-150200.8.65.1
fixed
suse enterprise sap 15 SP1
68.7.0-3.77.1
fixed
suse enterprise sap 15 SP2
68.7.0-3.77.1
fixed
suse enterprise sap 15 SP3
78.10.0-8.23.1
fixed
suse enterprise sap 15 SP4
91.8.0-150200.8.65.1
fixed
suse enterprise server 15 SP1
68.7.0-3.77.1
fixed
suse enterprise server 15 SP2
68.7.0-3.77.1
fixed
suse enterprise server 15 SP3
78.10.0-8.23.1
fixed
suse enterprise server 15 SP4
91.8.0-150200.8.65.1
fixed
suse enterprise workstation 15 SP1
68.7.0-3.77.1
fixed
suse enterprise workstation 15 SP2
68.7.0-3.77.1
fixed
suse enterprise workstation 15 SP3
78.10.0-8.23.1
fixed
suse enterprise workstation 15 SP4
91.8.0-150200.8.65.1
fixed
Red Hat logo
Red Hat Enterprise Linux Releases
Red Hat Product
Release
firefox
RHEL 6
0:68.6.1-1.el6_10
fixed
RHEL 7
0:68.6.1-1.el7_8
fixed
thunderbird
RHEL 6
0:68.7.0-1.el6_10
fixed
RHEL 7
0:68.7.0-1.el7_8
fixed
Common Weakness Enumeration
References
https://bugzilla.mozilla.org/show_bug.cgi?id=1626728
https://usn.ubuntu.com/4335-1/
https://www.mozilla.org/security/advisories/mfsa2020-11/
https://www.mozilla.org/security/advisories/mfsa2020-14/
https://bugzilla.mozilla.org/show_bug.cgi?id=1626728
https://usn.ubuntu.com/4335-1/
https://www.mozilla.org/security/advisories/mfsa2020-11/
https://www.mozilla.org/security/advisories/mfsa2020-14/
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-6820