HTTP response splitting in Mozilla Firefox and Mozilla Thunderbird - CVE-2021-29991
Published: August 18, 2021
Vulnerability identifier: #VU55935
CSH Severity: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2021-29991
CWE-ID: CWE-113
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Mozilla Firefox
Mozilla Thunderbird
Mozilla Firefox
Mozilla Thunderbird
Software vendor:
Mozilla
Mozilla
Description
The vulnerability allows a remote attacker to perform HTTP splitting attacks.
The vulnerability exists due to the affected software incorrectly accepts a newline in a HTTP/3 header, interpretting it as two separate headers. A remote attacker can perform a header splitting attack against servers using HTTP/3.
Remediation
Install updates from vendor's website.