Revealing the exploitability of heap overflow through PoC analysis

The exploitable heap layouts are used to determine the exploitability of heap vulnerabilities in general-purpose applications. Prior studies have focused on using fuzzing-based methods to generate more exploitable heap layouts. However, the exploitable heap layout cannot fully demonstrate the exploitability of a vulnerability, as it is uncertain whether the attacker can control the data covered by the overflow. In this paper, we propose the Heap Overflow Exploitability Evaluator (Hoee), a new approach to automatically reveal the exploitability of heap buffer overflow vulnerabilities by evaluating proof-of-concepts (PoCs) generated by fuzzers. Hoee leverages several techniques to collect dynamic information at runtime and recover heap object layouts in a fine-grained manner. The overflow context is carefully analyzed to determine whether the sensitive pointer is corrupted, tainted, or critically used. We evaluate Hoee on 34 real-world CVE vulnerabilities from 16 general-purpose programs. The results demonstrate that Hoee accurately identifies the key factors for developing exploits in vulnerable contexts and correctly recognizes the behavior of overflow.