Vulnerability Monitor

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CVE-2021-29991

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.

Published

2021-11-03T01:15:07.060

Last Modified

2024-11-21T06:02:07.710

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 8.1 (HIGH)

CVSSv2 Vector

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

  • Access Vector: NETWORK
  • Access Complexity: MEDIUM
  • Authentication: NONE
  • Confidentiality Impact: PARTIAL
  • Integrity Impact: PARTIAL
  • Availability Impact: NONE
Exploitability Score

8.6

Impact Score

4.9

Weaknesses
  • Type: Primary
    CWE-444
Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application mozilla firefox < 91.0.1 Yes
Application mozilla thunderbird < 91.0.1 Yes
References