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
NISTNIST
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
mozillaCNA
---
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CVEADP
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CISA-ADPADP
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: 88%
VendorProductVersion
mozillafirefox
𝑥
< 74.0.1
mozillafirefox_esr
𝑥
< 68.6.1
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
bullseye
115.14.0esr-1~deb11u1
fixed
bullseye (security)
128.4.0esr-1~deb11u1
fixed
bookworm
115.14.0esr-1~deb12u1
fixed
bookworm (security)
128.4.0esr-1~deb12u1
fixed
trixie
128.3.1esr-2
fixed
sid
128.4.0esr-1
fixed
thunderbird
bullseye
1:115.12.0-1~deb11u1
fixed
bullseye (security)
1:128.4.0esr-1~deb11u1
fixed
bookworm
1:115.12.0-1~deb12u1
fixed
bookworm (security)
1:128.4.0esr-1~deb12u1
fixed
sid
1:128.4.0esr-1
fixed
trixie
1:128.4.0esr-1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
firefox
focal
Fixed 75.0+build3-0ubuntu1
released
eoan
Fixed 74.0.1+build1-0ubuntu0.19.10.1
released
bionic
Fixed 74.0.1+build1-0ubuntu0.18.04.1
released
xenial
Fixed 74.0.1+build1-0ubuntu0.16.04.1
released
trusty
dne
thunderbird
focal
Fixed 1:68.7.0+build1-0ubuntu1
released
eoan
Fixed 1:68.7.0+build1-0ubuntu0.19.10.1
released
bionic
Fixed 1:68.7.0+build1-0ubuntu0.18.04.1
released
xenial
Fixed 1:68.7.0+build1-0ubuntu0.16.04.2
released
trusty
dne