CVE-2021-29991

2021-11-0300:04:17

mozilla

www.cve.org

AI Score

8.1

Confidence

High

EPSS

0.002

Percentile

53.0%

JSON

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.

CNA Affected

[
  {
    "product": "Firefox",
    "vendor": "Mozilla",
    "versions": [
      {
        "lessThan": "91.0.1",
        "status": "affected",
        "version": "unspecified",
        "versionType": "custom"
      }
    ]
  },
  {
    "product": "Thunderbird",
    "vendor": "Mozilla",
    "versions": [
      {
        "lessThan": "91.0.1",
        "status": "affected",
        "version": "unspecified",
        "versionType": "custom"
      }
    ]
  }
]