otelgrpc DoS vulnerability due to unbound cardinality metrics

Summary The grpc Unary Server Interceptor opentelemetry-go-contrib/instrumentation/google.golang.org/grpc/otelgrpc/interceptor.go // UnaryServerInterceptor returns a grpc.UnaryServerInterceptor suitable // for use in a grpc.NewServer call. func UnaryServerInterceptor(opts …Option) grpc.UnaryServerInterceptor { out of the box adds labels net.peer.sock.addr net.peer.sock.port that have unbound cardinality. It leads to the server's potential memory exhaustion when many malicious requests are sent. Details An attacker can easily flood the peer address and port for requests. PoC Apply the attached patch to the example and run the client multiple times. Observe how each request will create a unique histogram and how the memory consumption increases during it. Impact In order to be affected, the program has to configure a metrics pipeline, use UnaryServerInterceptor, and does not filter any client IP address and ports via middleware or proxies, etc. Others It is similar to already reported vulnerabilities. GHSA-rcjv-mgp8-qvmr (open-telemetry/opentelemetry-go-contrib) GHSA-5r5m-65gx-7vrh (open-telemetry/opentelemetry-go-contrib) GHSA-cg3q-j54f-5p7p (prometheus/client_golang) Workaround for affected versions As a workaround to stop being affected, a view removing the attributes can be used. The other possibility is to disable grpc metrics instrumentation by passing otelgrpc.WithMeterProvider option with noop.NewMeterProvider. Solution provided by upgrading In PR #4322, to…Read More