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Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') in io.netty:netty-all

CVE-2025-58056

  • io.netty:netty-all
  • io.netty:netty-codec-http
Low
2.9/10

Summary

Netty is an asynchronous event-driven network application framework for development of maintainable high performance protocol servers and clients. In versions through 4.1.124.Final, 4.2.x through 4.2.4.Final, and 5.0.0Alpha1 through 5.0.0.Alpha2 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.

  • LOW
  • NETWORK
  • HIGH
  • UNCHANGED
  • NONE
  • NONE
  • NONE
  • NONE

CWE-444 - HTTP Request Smuggling

Entities such as web servers, web caching proxies, and application firewalls could parse HTTP requests differently. When there are two or more such entities in the path of an HTTP request, an attacker can send a specially crafted HTTP request that is seen as two different sets of requests by the attacked devices, allowing the attacker to smuggle a request into one device without the other device being aware of it. Such a vulnerability can prove devastating, for it enables further attacks on the application, like web cache poisoning, session hijacking, cross-site scripting, security bypassing, and sensitive information exposure.

References

Advisory Timeline

  • Published