MKP: Unbounded Pod Log Read via Attacker-Controlled `limitBytes`/`tailLines` Causes Memory Exhaustion

Summary

MKP is a Model Context Protocol server for Kubernetes. Prior to 0.4.1, cmd/server/main.go exposes the default HTTP endpoint and pkg/mcp/server.go registers the unauthenticated get_resource tool, which accepts attacker-controlled limitBytes and tailLines values for the pods logs subresource. buildPodLogOpts() in pkg/k8s/subresource.go parses those values as unbounded int64 parameters, and defaultGetPodLogs() copies the returned Kubernetes log stream through io.Copy into an in-memory bytes.Buffer without an application-side cap. A remote attacker who can reach the default port 8080 MCP endpoint and select a pod with sufficiently large accumulated logs can send one tools/call request that causes large allocations and additional response copies, while the request-frequency limiter does not constrain per-request volume. This can exhaust process memory, terminate the MKP server, and deny the MCP service; observed testing showed more than one GiB of RSS growth while handling a 128 MiB requested stream. This issue is fixed in version 0.4.1.