CVE-2021-29991

Published: Nov 3, 2021Modified: Nov 21, 2024

8.1

Vector

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

Exploitability: 2.8 / Impact: 5.2

Source: NVD

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.

Affected (2)

Products: Mozilla: Firefox, Thunderbird

Mozilla

2 products

Firefox

Thunderbird

Configuration A

2 vulnerable

Vulnerable Software	Affected Versions
Mozilla Firefox	Before 91.0.1
Mozilla Thunderbird	Before 91.0.1

Related CWEs

CWE-444

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

References (4)

https://bugzilla.mozilla.org/show_bug.cgi?id=1724896

Source: security@mozilla.org

Permissions Required

https://www.mozilla.org/security/advisories/mfsa2021-37/

Source: security@mozilla.org

Vendor Advisory

https://bugzilla.mozilla.org/show_bug.cgi?id=1724896

Source: af854a3a-2127-422b-91ae-364da2661108

Permissions Required

https://www.mozilla.org/security/advisories/mfsa2021-37/

Source: af854a3a-2127-422b-91ae-364da2661108

Vendor Advisory

Timeline

No history available yet.