Dwarf Frankenstein is still in your memory: tiny code reuse attacks

Code reuse attacks such as return oriented programming and jump oriented programming are the most popular exploitation methods among attackers. A large number of practical and non-practical defenses are proposed that differ in their overhead, the source code requirement, detection rate and implementation dependencies. However, a usual aspect among these methods is consideration of the common behaviour of code reuse attacks, which is the construction of a gadget chain. Therefore, the implication of a gadget and the minimum size of an attack chain are a matter of controversy. Conservative or relaxed thresholds may cause false positive and false negative alarms, respectively. The main contribution of this paper is to provide a tricky aspect of code reuse techniques, called tiny code reuse attacks (Tiny-CRA) that demonstrates the ineffectiveness of the threshold based detection methods. We show that with bare minimum assumptions, Tiny-CRA can reduce the size of a gadget chain in shuch a way that no distinction can be detected between normal behavior of a program and a code-reuse execution. To do so, we exhibit our Tiny-CRA primitives and introduce a useful gadget set available in libc. We demonstrate the effectiveness of our approach by implementing nine different shell-codes and exploiting real-world buffer overflow vulnerability in HT Editor 2.0.20.