Autodafé: an Act of Software Torture

Automated vulnerability searching tools have led to a dramatic increase of the rate at which such flaws are discovered. One particular searching technique is fault injection – i.e. insertion of random data into input files, buffers or protocol packets, combined with a systematic monitoring of memory violations. Even if these tools allow to uncover a lot of vulnerabilities, they are still very primitive; despite their poor efficiency, they are useful because of the very high density of such vulnerabilities in modern software. This paper presents an innovative buffer overflow uncovering technique, which uses a more thorough and reliable approach. This technique, called fuzzing by weighting attacks with markers, is a specialized kind of fault injection, which does not need source code or special compilation for the monitored program. As a proof of concept of the efficiency of this technique, a tool called Autodafé has been developed. It allows to detect automatically an impressive number of buffer overflow vulnerabilities. keywords: fuzzer, buffer overflow, weighting attacks with markers technique, fault injection, autodafe.