Sadullah Canakci , Nikolay Matyunin, Kalman Graffi, Manuel Egele, "TargetFuzz: Using DARTs to Guide Directed Greybox Fuzzers", The 17th ACM ASIA Conference on Computer and Communications Security (ACM ASIACCS 2022), 2022.

Software development is a continuous and incremental process. Developers continuously improve their software in small batches rather than in one large batch. The high frequency of small batches makes it essential to use effective testing methods that detect bugs under limited testing time. To this end, researchers propose directed greybox fuzzing (DGF) which aims to generate test cases towards stressing certain target sites. Different from the coverage-based greybox fuzzing (CGF) which aims to maximize code coverage in the whole program, the goal of DGF is to cover potentially buggy code regions (e.g., a recently modifed program region). While prior works improve several aspects of DGF (such as power scheduling, input prioritization, and target selection), little attention has been given to improving the seed selection process. Existing DGF tools use seed corpora mainly tailored for CGF (i.e., a set of seeds that cover different regions of the program). We observe that using CGF-based corpora limits the bug-finding capability of a directed greybox fuzzer. To mitigate this shortcoming, we propose TargetFuzz, a mechanism that provides a DGF tool with a target-oriented seed corpus. We refer to this corpus as DART corpus, which contains only ‘close’ seeds to the targets. This way, DART corpus guides DGF to the targets, thereby exposing bugs even under limited fuzzing time. Evaluations on 34 real bugs show that AFLGo (a state-of-the-art directed greybox fuzzer), when equipped with DART corpus, finds 10 additional bugs and achieves 4.03x speedup, on average, in the time-to-exposure compared to a generic CGF-based corpus.