Not rated
CVE-2021-29991 Firefox incorrectly accepted a newline in a HTTP/3 header, interpretting it as two separate headers
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 < 91.0.1 and Thunderbird < 91.0.1.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Firefox 91.0 | earliest → < 91.0.1 | 91.0.1 |
| Thunderbird 91.0 | earliest → < 91.0.1 | 91.0.1 |
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