GHSA-j93g-rp6m-j32m Arc: Unauthenticated access to Go debug pprof endpoints leaks runtime state and enables CPU-burn DoS

• Go github.com/basekick-labs/arc: < 0.0.0-20260520170331-32a4091fb949 → fixed in 0.0.0-20260520170331-32a4091fb949

Summary Arc registers Go's `net/http/pprof` handlers at `/debug/pprof/*` via `app.Use(pprof.New())` in `internal/api/server.go`, and `/debug/pprof` is added to `PublicPrefixes` in `cmd/arc/main.go`. The auth middleware short-circuits before the token check on prefix match, so the endpoints are reachable without any authentication. Impact Any network-reachable caller (no token required) can: • Fetch `/debug/pprof/heap` — leaks in-memory state: live SQL strings, decoded msgpack records, decompressed request bodies, cached `*TokenInfo` (the auth cache keys on SHA-256 of the plaintext token at `auth.go:543`). • Fetch `/debug/pprof/goroutine?debug=2` — leaks call stacks, identifying internal code paths. • Fetch `/debug/pprof/profile?seconds=N` — pins a CPU core for arbitrary duration. Trivial DoS amplification (one short HTTP request → minutes of server CPU). • Fetch `/debug/pprof/trace` — long-duration execution trace, similar DoS profile. No authentication, no rate limiting, no resource bound on the `seconds` parameter. Patches https://github.com/Basekick-Labs/arc/releases/tag/v26.06.1 Planned mitigation: 1. Gate pprof registration behind an env var (`ARC_DEBUG_PPROF=1`) that defaults to off. 2. When enabled, bind pprof to a separate localhost-only listener (`127.0.0.1:6060` via dedicated `net/http` server) so it's never reachable from the public API port. 3. Remove `/debug/pprof` from `PublicPrefixes`. 4. Fix the `HasPrefix` bug where `"/debug/pprofX"` matches `"/debug/pprof"`. Workarounds • Block `/debug/pprof*` at a reverse proxy / load balancer in front of Arc. • Restrict Arc's API port to known-trusted networks via firewall rules. • Patch the running build: comment out `app.Use(pprof.New())` in `internal/api/server.go` and rebuild. Credits Reported by Alex Manson (@NeuroWinter, https://neurowinter.com/) on 2026-05-19.