2026-10-29 –, Workshop Room
Coverage-guided fuzzing is a software testing methodology that is effective at finding vulnerabilities by automatically and continually making small changes to the program's input and observing its effect on the path a program takes. This hands-on workshop aims to give you the tools needed to set up a simple working fuzzing environment for your own targets.
Fuzz testing is a broad area of software testing that involves making many, (informed) random mutations on input with the goal of finding bugs. This workshop focuses on coverage-guided fuzzing methodologies where the path a program takes for specific inputs is used to decide which inputs to further mutate. This method of testing allows for gaining more coverage across the program faster but requires specific preparation for the target.
The following topics will be covered during the session:
- Compiling an instrumented binary
- Creating an initial corpus
- Perform coverage-based fuzzing
- Interpreting results
For this workshop no prior fuzzing knowledge is required, but limited familiarity with C and basic understanding of memory layout are assumed.
IMPORTANT: The workshop requires a laptop with Docker installed.
Sebastiaan is an Ethical Hacker at KPN with an interest in binary analysis and exploitation, system security and breaking programs in general. Before that, he worked as an incident responder and forensic analyst at KPN-CERT. Whenever opportunity arises, he can be found at CTF events.
Frank Cozijnsen is a seasoned ethical hacker at KPN, the leading telecommunications provider in the Netherlands, where he has worked for over 25 years. Previously, he held roles as a VoIP engineer and system administrator within the same organization.
Frank likes to focus on assessing mobile networking equipment and telecom infrastructure, with a particular interest in binary exploitation and hacking complex environments. He likes to play CTF's and has discovered vulnerabilities in several products using custom fuzzing techniques.