fuzzing
termsecurityprogramminghacking
Feeding a program vast quantities of malformed or random input to see what makes it crash.
A crash is a lead, since a program that mishandles input badly enough to die may mishandle it exploitably, and fuzzers find in hours what code review misses for years. Modern coverage-guided fuzzers like AFL and libFuzzer mutate inputs and keep the ones that reach new code paths, which is why they are paired with sanitizers that turn silent corruption into a loud, reproducible failure. It sits on both sides of the fence: the same tool serves a vendor hardening a parser and a researcher hunting for bugs in it.
Also known as: fuzz testing, fuzzer, AFL