Mastodon is a free, open-source social network server based on ActivityPub. When performing outgoing HTTP queries, Mastodon sets a timeout on individual read operations. Prior to versions 3.5.9, 4.0.5, and 4.1.3, a malicious server can indefinitely extend the duration of the response through slowloris-type attacks. This vulnerability can be used to keep all Mastodon workers busy for an extended duration of time, leading to the server becoming unresponsive. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue.
www.openwall.com/lists/oss-security/2023/07/06/7
github.com/mastodon/mastodon/commit/c5929798bf7e56cc2c79b15bed0c4692ded3dcb6
github.com/mastodon/mastodon/releases/tag/v3.5.9
github.com/mastodon/mastodon/releases/tag/v4.0.5
github.com/mastodon/mastodon/releases/tag/v4.1.3
github.com/mastodon/mastodon/security/advisories/GHSA-9pxv-6qvf-pjwc