GHSA-54w6-vxfh-fw7f Http4s improperly parses User-Agent and Server headers

• Maven org.http4s:http4s-core_2.13: >= 0.1.0, < 0.21.34 → fixed in 0.21.34 • Maven org.http4s:http4s-core_2.13: >= 0.22.0, < 0.22.15 → fixed in 0.22.15 • Maven org.http4s:http4s-core_2.13: >= 0.23.0, < 0.23.17 → fixed in 0.23.17 • Maven org.http4s:http4s-core_2.13: >= 1.0.0-M1, < 1.0.0-M38 → fixed in 1.0.0-M38 • Maven org.http4s:http4s-core_2.10: >= 0.1.0, <= 0.9.3 (no fix yet) • Maven org.http4s:http4s-core_2.11: >= 0.1.0, <= 0.21.0-M1 (no fix yet) • Maven org.http4s:http4s-core_2.12: >= 0.1.0, < 0.21.34 → fixed in 0.21.34 • Maven org.http4s:http4s-core_2.12: >= 0.22.0, < 0.22.15 → fixed in 0.22.15 • Maven org.http4s:http4s-core_2.12: >= 0.23.0, < 0.23.17 → fixed in 0.23.17 • Maven org.http4s:http4s-core: >= 1.0.0-M1, <= 1.0.0-M30 (no fix yet)

Impact The `User-Agent` and `Server` header parsers are susceptible to a fatal error on certain inputs. In http4s, modeled headers are lazily parsed, so this only applies to services that explicitly request these typed headers. v0.21.x ```scala val unsafe: Option[`User-Agent`] = req.headers.get(`User-Agent`) ``` v0.22.x, v0.23.x, v1.x ```scala val unsafe: Option[`User-Agent`] = req.headers.get[`User-Agent`] val alsoUnsafe: Option[`Server`] = req.headers.get[Server] ``` Patches Fixes are released in 0.21.34, 0.22.15, 0.23.17, and 1.0.0-M38. Workarounds Use the weakly typed header interface v0.21.x ```scala val safe: Option[Header] = req.headers.get("User-Agent".ci) // but don't do this val unsafe = header.map(_.parsed) ``` v0.22.x, v0.23.x, v1.x ```scala val safe: Option[Header] = req.headers.get(ci"User-Agent") ```