Netty is vulnerable to request smuggling due to incorrect parsing of chunk extensions
Summary
Netty is vulnerable to request smuggling due to incorrect parsing of chunk extensions
Original description
The description as published by the source.
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.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2025-58056 netty Fixed in: 1:4.1.48-4+deb11u3
- Ubuntu UBUNTU-CVE-2025-58056 netty
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- patch github.com
- patch github.com
- report github.com
- report github.com
- web datatracker.ietf.org
- web w4ke.info