HTTP Request Smuggling The advisory has been revoked - it doesn't affect any version of package thunderbird  (opens in a new tab)


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EPSS
0.34% (57th percentile)

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  • Snyk IDSNYK-UBUNTU2004-THUNDERBIRD-1567410
  • published19 Aug 2021
  • disclosed3 Nov 2021

Introduced: 19 Aug 2021

CVE-2021-29991  (opens in a new tab)
CWE-444  (opens in a new tab)

Amendment

The Ubuntu security team deemed this advisory irrelevant for Ubuntu:20.04.

NVD Description

Note: Versions mentioned in the description apply only to the upstream thunderbird package and not the thunderbird package as distributed by Ubuntu.

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.