ShellHub is a centralized SSH gateway. Prior to 0.24.2, GET /api/namespaces/:tenant returns the full namespace object — including the members list (user IDs, e-mails, roles), settings, and device counts — to any caller authenticated by an API Key, for any tenant, regardless of the API Key's own tenant scope. The handler conditionally skips the membership check when the user ID (X-ID) is absent, which is exactly the case for API Key authentication. This vulnerability is fixed in 0.24.2.

Affected: Go: github.com/shellhub-io/shellhub

## Summary `GET /api/namespaces/:tenant` returns the full namespace object — including the members list (user IDs, e-mails, roles), settings, and device counts — to any caller authenticated by an **API Key**, for any tenant, regardless of the API Key's own tenant scope.

The handler conditionally skips the membership check when the user ID (`X-ID`) is absent, which is exactly the case for API Key authentication.

## Affected versions ShellHub Community v0.24.1 (validated).

## Root cause `api/routes/nsadm.go:75-102` — membership check is skipped when `c.ID()` is nil:

```go var uid string if c.ID() != nil { uid = c.ID().ID }

ns, err := h.service.GetNamespace(c.Ctx(), req.Tenant) if err != nil || ns == nil { return c.NoContent(http.StatusNotFound) }

if uid != "" { // ⚠️ skipped when API Key is used if _, ok := ns.FindMember(uid); !ok { return c.NoContent(http.StatusForbidden) } }

return c.JSON(http.StatusOK, ns) ```

`AuthRequest` (`api/routes/auth.go:53-64`) sets only `X-Tenant-ID`, `X-Role`, and `X-API-KEY` for API Key authentication — never `X-ID`. So `c.Request().Header.Get("X-ID")` returns `""`, `c.ID()` returns `nil`, and the membership check is bypassed.

## Proof of concept (validated live against v0.24.1)

```bash # Attacker authenticates in their own namespace and mints an API Key ATTACKER_TOKEN=$(curl -s -X POST http://target/api/login \ -H 'Content-Type: appli…