Finding Buffer Overflow Inducing Loops in Binary Executables

Vulnerability analysis is one among the important components of overall software assurance practice. Buffer overflow (BoF) is one example of the such vulnerabilities and it is still the root cause of many effective attacks. A general practice to find BoF is to look for the presence of certain functions that manipulate string buffers, like the strcpy family. In these functions, data is moved from one buffer to another, within a loop, without considering destination buffer size. We argue that similar behaviour may also be present in many other functions that are coded separately, and therefore are equally vulnerable. In the present work, we investigate the detection of such functions by finding loops that exhibit similar behaviour. We call such loops Buffer Overflow Inducing Loops (BOIL). We implemented a lightweight static analysis to detect BOILs, and evaluated it on real-world x86 binary executables. The results obtained show that this (simple but yet efficient) vulnerability pattern happens to be very effective in practice to retrieve real vulnerabilities, providing a drastic reduction of the part of the code to be analysed.