EnvoyCon North America 2022

How can we be assured of the correctness and safety of the many Envoy parsers and state machines in the presence of untrusted or adversarial input? While developers cover main scenarios using tests, complex edge cases may be missed. Adversaries may be able to exploit these cases to trigger denial of service attacks, access Envoy process memory remotely, or trigger remote execution of malicious code. Fuzzing is an automated software testing technique that provides randomized input to the system under test (SUT). Some tests may use a variety of sanitizers to check for violations of memory safety, check for invariants expressed as assert statements or abnormal program terminations or timeouts. Other tests may compare behavior of different SUTs to the same input. This talk will include an overview of different fuzzers in Envoy, the OSS-Fuzz infrastructure for running fuzz tests, some bugs fuzz tests discovered, and examples of creating specific fuzz tests for ESF components in Envoy.