GHSA-w4c6-7r69-w7j9: klever-go: REST API slow-header connection exhaustion via Gin Engine.Run

The Klever seednode REST API starts a Gin engine with Engine.Run(restAPIInterface). In Gin v1.9.1, Engine.Run calls Go’s default http.ListenAndServe, which constructs an HTTP server without application-level ReadHeaderTimeout, ReadTimeout, or MaxHeaderBytes limits.

An unauthenticated client that can reach a REST listener bound with Klever’s documented --rest-api-interface :8080 all-interface option can hold incomplete HTTP headers open indefinitely. In a local proof against the real cmd/seednode/api.Start path on v1.7.17, 120 slow-header connections caused 20/20 legitimate /log probes to fail with accept: too many open files. A fixed control using the same Gin router behind an explicit http.Server with ReadHeaderTimeout, ReadTimeout, and MaxHeaderBytes retained 0 slow connections and served 20/20 probes.

This report is distinct from the P2P advisories and from my direct-message goroutine report. This finding concerns Klever-owned HTTP REST startup code (cmd/seednode/api and network/api) using Gin Engine.Run without server-level header deadlines. It does not depend on MultiDataInterceptor, Batch.Decompress, libp2p, malformed P2P messages, or direct-message goroutine spawning.