Fedora 34 : firefox (2021-74b76e593a)

high Nessus Plugin ID 152831



The remote Fedora host is missing one or more security updates.


The remote Fedora 34 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2021-74b76e593a advisory.

- 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. (CVE-2021-29991)

- - New upstream update (91.0.1) - Fixes font crashes (https://bugzilla.mozilla.org/1726515) (FEDORA-2021-74b76e593a) Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.


Update the affected firefox package.

See Also


Plugin Details

Severity: High

ID: 152831

File Name: fedora_2021-74b76e593a.nasl

Version: 1.4

Type: local

Agent: unix

Published: 8/25/2021

Updated: 1/20/2022

Supported Sensors: Frictionless Assessment Agent, Nessus Agent

Risk Information


Risk Factor: Medium

Score: 6


Risk Factor: Medium

Base Score: 5.8

Temporal Score: 4.3

Vector: AV:N/AC:M/Au:N/C:P/I:P/A:N

Temporal Vector: E:U/RL:OF/RC:C

CVSS Score Source: CVE-2021-29991


Risk Factor: High

Base Score: 8.1

Temporal Score: 7.1

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:fedoraproject:fedora:34, p-cpe:/a:fedoraproject:fedora:firefox

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 8/24/2021

Vulnerability Publication Date: 8/24/2021

Reference Information

CVE: CVE-2021-29991