Chisel

Chisel is a lightweight tool designed for creating fast TCP/UDP tunnels transported over HTTP, with security provided via SSH. It is particularly useful for passing through firewalls and providing a secure endpoint into networks. The single executable includes both client and server functionality, making it easy to deploy in various scenarios.

Common use cases include tunneling traffic through restrictive firewalls, enabling remote access to internal services, and creating secure proxies. It supports both TCP and UDP protocols, offering flexibility for different networking needs. Chisel is maintained as an open-source project and is available in Kali Linux repositories.

The tool is referenced in advanced training like PEN-200 for HTTP tunneling theory and practice, and PEN-300 for Windows lateral movement techniques such as reverse RDP proxying.

Chisel operates by encapsulating TCP/UDP traffic within HTTP requests and responses, secured using SSH for encryption and authentication. It runs in server mode to listen for connections or client mode to establish tunnels, leveraging HTTP to evade deep packet inspection while maintaining high performance through efficient multiplexing.