Red Hat JBoss EAP: CVE-2025-58056: HTTP Request/Response Smuggling

Netty is an asynchronous event-driven network application framework for development of maintainable high performance protocol servers and clients. In versions 4.1.124.Final, and 4.2.0.Alpha3 through 4.2.4.Final, Netty incorrectly accepts standalone newline characters (LF) as a chunk-size line terminator, regardless of a preceding carriage return (CR), instead of requiring CRLF per HTTP/1.1 standards. When combined with reverse proxies that parse LF differently (treating it as part of the chunk extension), attackers can craft requests that the proxy sees as one request but Netty processes as two, enabling request smuggling attacks. This is fixed in versions 4.1.125.Final and 4.2.5.Final.. A flaw in Netty’s HTTP/1.1 chunked encoding parser allows newline (LF) characters in chunk extensions to be incorrectly treated as the end of the chunk-size line instead of requiring the proper CRLF sequence. This discrepancy can be exploited in rare cases where a reverse proxy interprets the same input differently, potentially enabling HTTP request smuggling attacks such as bypassing access controls or corrupting responses.