high8.1
CVE-2021-29991
Firefox incorrectly accepted a newline in a HTTP/3 header, interpretting it as two separate headers.
Impact
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 products
| Vendor | Product | Affected versions |
|---|---|---|
| Mozilla | Firefox | before 91.0.1 |
| Mozilla | Thunderbird | before 91.0.1 |