CVE-2021-29479: HTTP Request Smuggling

A user supplied X-Forwarded-Host header can be used to perform cache poisoning of a cache fronting a Ratpack server if the cache key does not include the X-Forwarded-Host header as a cache key. Users are only vulnerable if they do not configure a custom PublicAddress instance. F, by default, Ratpack utilizes an inferring version of PublicAddress which is vulnerable. This can be used to perform redirect cache poisoning where an attacker can force a cached redirect to redirect to their site instead of the intended redirect location. The vulnerability was patched in Ratpack As a workaround, ensure that ServerConfigBuilder::publicAddress correctly configures the server in production.