🎯 What You'll Learn
- Detect request-smuggling desync conditions
- Exploit CL.TE and TE.CL discrepancies
- Inject via CRLF
- Abuse HTTP/2 to HTTP/1 downgrades
Overview
When two servers disagree about where a request ends, you can smuggle a second request past security controls. This lab covers CL.TE/TE.CL desync, CRLF injection and HTTP/2 downgrades.
Core Topics
- Front-end/back-end parsing
- Desync detection
- Response queue poisoning
- HTTP/2 downgrade
Prerequisites
A working KaliRange lab environment and comfort with the Linux command line.
Recommended Workflow
- Spin up the target in your KaliRange lab environment and confirm connectivity.
- Enumerate the target thoroughly before touching any exploit — information first.
- Reproduce each technique by hand so you understand why it works, not just the command.
- Capture evidence (commands, output, screenshots) as you go.
- Write a short note on how a defender would detect or prevent what you just did.
Only ever run these techniques against systems you own or have explicit written permission to test. Practise inside your own KaliRange lab.
Your Goal
Work through every task in your own lab, document your findings as you would on a real engagement, then note the defensive takeaways.
Ready to practise. Work through the steps above at your own pace, then move on to a related lab.