HIGH 8.1
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.
CVSS v3
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
EPSS
0.3%
percentile 56.9%
Affected tracked apps
Vulnerable CPE configurations
| Vendor | Product | Platform | Versions | CPE 2.3 URI |
|---|---|---|---|---|
| mozilla | thunderbird | Windows | <91.0.1 | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* |