zzuf is a transparent application input fuzzer. It works by intercepting file operations and changing random bits in the program's input. zzuf's behaviour is deterministic, making it easy to reproduce bugs. For instructions and examples on how to use zzuf, see the manual page and the website at <http://caca.zoy.org/wiki/zzuf>. This version has been patched by CERT for easier debugging and is used with the CERT Basic Fuzzing Framework (BFF).