Improper Input Validation

Summary

Http4s is a Scala interface for HTTP services. Starting with version 0.1.x prior to 0.21.34, 0.22.x prior to 0.22.15, 0.23.x prior to 0.23.17, and 1.0.0-x prior to 1.0.0-M38, 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. Fixes are released in 0.21.34, 0.22.15, 0.23.17, and 1.0.0-M38. As a workaround, use the weakly typed header interface.