CVE-2021-29991 Information

Description

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.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Reference

https://bugzilla.mozilla.org/show_bug.cgi?id=1724896 https://www.mozilla.org/security/advisories/mfsa2021-37/

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

REQUIRED

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

NONE

Base Severity

8.1