Signal K Server: Privilege Escalation by Admin Role Injection via /enableSecurity
Date: 2026-04
Affected: npm/signalk-server
Attack vector: auth-bypass
Category: vulnerability-disclosure
Severity: Critical
CVE: CVE-2026-33950
CWE: CWE-285
CWE-288
CWE-862
CVSS: 9.4 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L)

## Summary According to SignalK's security documentation, when a server is first initialized without security enabled, the **/skServer/enableSecurity** endpoint is intentionally exposed to allow the owner to set up the initial admin account. This initial open access is by design. However, the critical vulnerability is that this route is never deregistered or disabled after the initial successful setup. Even after the genuine administrator has created their account, restarted the server, and activated token security, the **/skServer/enableSecurity** route remains perpetually open. Furthermore, the endpoint explicitly trusts the **type** field provided in the request body, passing it directly into the server's security configuration without validation. Because the route remains permanently listening, any unauthenticated user can call this endpoint at any time to silently inject a new, fully privileged admin account alongside the legitimate ones. ## Vulnerable Root Cause File: src/serverroutes.ts (Lines 685-754) ``` if (app.securityStrategy.getUsers(getSecurityConfig(app)).length === 0) { app.post( `${SERVERROUTESPREFIX}/enableSecurity`, (req: Request, res: Response) => { // ... function addUser(request: Request, response: Response, securityStrategy: SecurityStrategy, config?: any) { // [!VULNERABLE] Passes the entire JSON request body directly to the security strategy securityStrategy.addUser(config, request.body, (err,


Mitigations:

Architectural layers (MAESTRO):