Fuzzing: The Art of Controlled Chaos

Fuzzing (or Fuzz Testing) is an automated software testing technique that involves providing invalid, unexpected, or random data as input to a computer program. The program is then monitored for exceptions such as crashes, failing built-in code assertions, or potential memory leaks.

Types of Fuzzers:

• Dumb Fuzzers: Generate inputs with little or no knowledge of the input structure (e.g., bit flipping, random strings).
• Smart Fuzzers (Generational): Understand the input format and generate inputs based on a model or grammar.
• Mutation-based Fuzzers: Take valid inputs and mutate them to create new test cases.

Why Fuzz?

• Excellent for finding memory corruption bugs (buffer overflows, use-after-free).
• Can uncover unexpected behavior and crashes that other testing methods miss.
• Often used to find zero-day vulnerabilities.

Tools like AFL (American Fuzzy Lop) and libFuzzer are popular.