CVE-2021-29991

EUVD-2021-16450
Firefox incorrectly accepted a newline in a HTTP/3 header, interpretting it as two separate headers. This allowed for a header splitting attack against servers using HTTP/3. This vulnerability affects Firefox < 91.0.1 and Thunderbird < 91.0.1.
HTTP Request/Response Smuggling
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
8.1 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 56%
Affected Products (NVD)
VendorProductVersion
mozillafirefox
𝑥
< 91.0.1
mozillathunderbird
𝑥
< 91.0.1
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
firefox
sid
132.0.1-1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
firefox
bionic
Fixed 91.0.1+build1-0ubuntu0.18.04.1
released
focal
Fixed 91.0.1+build1-0ubuntu0.20.04.1
released
hirsute
Fixed 91.0.1+build1-0ubuntu0.21.04.1
released
impish
Fixed 91.0.1+build1-0ubuntu1
released
jammy
Fixed 91.0.1+build1-0ubuntu1
released
kinetic
Fixed 91.0.1+build1-0ubuntu1
released
lunar
Fixed 91.0.1+build1-0ubuntu1
released
mantic
Fixed 91.0.1+build1-0ubuntu1
released
noble
Fixed 91.0.1+build1-0ubuntu1
released
trusty
dne
xenial
ignored
mozjs38
bionic
ignored
focal
dne
hirsute
dne
impish
dne
jammy
dne
kinetic
dne
lunar
dne
mantic
dne
noble
dne
trusty
dne
xenial
dne
mozjs52
bionic
ignored
focal
ignored
hirsute
dne
impish
dne
jammy
dne
kinetic
dne
lunar
dne
mantic
dne
noble
dne
trusty
dne
xenial
dne
mozjs68
bionic
dne
focal
ignored
hirsute
dne
impish
dne
jammy
dne
kinetic
dne
lunar
dne
mantic
dne
noble
dne
trusty
dne
xenial
dne
mozjs78
bionic
dne
focal
dne
hirsute
ignored
impish
ignored
jammy
ignored
kinetic
ignored
lunar
ignored
mantic
dne
noble
dne
trusty
dne
xenial
dne
thunderbird
bionic
Fixed 1:91.5.0+build1-0ubuntu0.18.04.1
released
focal
Fixed 1:91.5.0+build1-0ubuntu0.20.04.1
released
hirsute
ignored
impish
not-affected
jammy
not-affected
kinetic
not-affected
lunar
not-affected
mantic
not-affected
noble
not-affected
trusty
dne
xenial
ignored