Scapy is a powerful, Python-based tool for crafting, sending, sniffing, and manipulating network packets. Widely used in offensive security, Scapy enables security researchers to interact directly with protocols at a low level, build custom packets, and analyze unusual network behaviors.

Beyond traditional packet crafting, Scapy can also be used for offensive fuzzing, CVE reproduction, and protocol analysis — making it a valuable asset in any red teamer or pentester’s toolkit.

This masterclass teaches you the practical foundations and advanced features of Scapy. You will learn how to craft and manipulate packets, interact with live networks, visualize packet flows, and automate scenarios using Scapy Automatons. You’ll also discover how to build your own DNS fuzzers and apply differential fuzzing techniques to trigger unexpected behaviors in target servers.

Finally, you’ll dive into real-world case studies where Scapy is used to reproduce known vulnerabilities (CVEs), including buffer overflows and parsing bugs.

This masterclass includes multiple hands-on labs, code walkthroughs, and practical demos to help you apply what you’ve learned immediately.

1. Introduction to Scapy

• Hands-on with packet manipulation (crafting and editing packets).

• Network interactions (sending and receiving packets).

• Visualization tools (graphical dumps, matplotlib).

• Advanced features with Automatons.

2. Creating and Fuzzing DNS Server Fuzzers using Scapy

• Introduction to DNS Server

• Introduction to fuzzing concepts.

• Introduction to differential fuzzing.

3. Reproduce CVEs with Scapy

• Study, explanation and rediscovery of multiple CVEs.

  • Buffer overflow and parsing vulnerabilities.