Modern applications are increasingly built on distributed architectures where dozens of services communicate with each other behind the scenes. To support this communication, organizations often rely on gRPC — a high-performance Remote Procedure Call (RPC) framework developed by Google. Unlike traditional REST APIs that primarily use JSON over HTTP/1.1, gRPC leverages Protocol Buffers (Protobuf) and HTTP/2 to enable fast, compact, and efficient communication between services.

Because of its speed, scalability, and strong language support, gRPC has become a popular choice for microservices, cloud-native applications, internal APIs, IoT platforms, and modern backend infrastructures. Companies adopting Kubernetes, service meshes, and distributed systems frequently expose critical functionality through gRPC endpoints.

However, this performance and abstraction often create a false sense of security. Many security teams are comfortable testing REST APIs but overlook gRPC services due to their binary nature, lack of human-readable traffic, and specialized tooling requirements. As a result, gRPC services may expose vulnerabilities such as insecure authentication, weak authorization, unsafe reflection, injection flaws, sensitive information disclosure, and misconfigured internal methods that remain undetected during conventional API assessments.