vulnerability
MFSA2021-37 Firefox: Security Vulnerabilities fixed in Firefox 91.0.1 and Thunderbird 91.0.1 (CVE-2021-29991)
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 6 | (AV:N/AC:M/Au:N/C:P/I:P/A:N) | Aug 16, 2021 | Aug 18, 2021 | Aug 11, 2025 |
Severity
6
CVSS
(AV:N/AC:M/Au:N/C:P/I:P/A:N)
Published
Aug 16, 2021
Added
Aug 18, 2021
Modified
Aug 11, 2025
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.
Solution
mozilla-firefox-upgrade-91_0_1
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