CVE-2021-29991

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

03/11/2021

Last modified:

04/11/2021

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

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N CVSS v3.1 Severity and Metrics:

Base Score: 8.10 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): Required
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): None

Base Score 3.x

8.10

Severity 3.x

HIGH

Vector 2.0

AV:N/AC:M/Au:N/C:P/I:P/A:N CVSS v2.0 Severity and Metrics:

Base Score: 5.80 MEDIUM
Vector: AV:N/AC:M/Au:N/C:P/I:P/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Medium
Authentication (Au): None
Confidentiality (C): Physical
Integrity (I): Physical
Availability (A): None