In recent years, REST API fuzzing has emerged to explore errors on a cloud service. Its
performance highly depends on the sequence construction and request generation.
However, existing REST API fuzzers have trouble generating long sequences with well-
constructed requests to trigger hard-to-reach states in a cloud service, which limits their
performance of finding deep errors and security bugs. Further, they cannot find the specific
errors caused by using undefined parameters during request generation. Therefore, in this …