CVE-2026-55501

## Summary The 9router dashboard login rate limiter derives the client identity from the attacker-controlled `X-Forwarded-For` HTTP header. When 9router is directly exposed, or deployed behind a reverse proxy that does not overwrite untrusted forwarding headers, a remote attacker can rotate the `X-Forwarded-For` value on each login attempt and receive a fresh rate-limit bucket every time. This bypasses the dashboard brute-force protection and makes the login lockout mechanism ineffective. ## Details | Component | File | Note | | ---------------------------- | --------------------------------- | --------------------------------------------------------------------------- | | Dashboard login rate limiter | `src/lib/auth/loginLimiter.js` | Uses `X-Forwarded-For` as the client identity without a trusted-proxy check | | Dashboard login route | `src/app/api/auth/login/route.js` | Calls `checkLock()` and `recordFail()` using the spoofable client identity | #### Vulnerable Code `src/lib/auth/loginLimiter.js`: ```js export function getClientIp(request) { const xff = request.headers.get("x-forwarded-for"); if (xff) return xff.split(",")[0].trim(); return request.headers.get("x-real-ip") || "unknown"; } ``` The returned value is used as the key for the in-memory rate-limit state: ```js const attempts = new Map(); // ip -> { fails, lockUntil, lockLevel, lastFailAt } ``` The login route uses this value when checking and recording failed login attempts: ```js export async function POST(request) { const ip = getClientIp(request); const lock = checkLock(ip); if (lock.locked) { return NextResponse.json( { error: `Too many failed attempts. Try again in ${lock.retryAfter}s.` }, { status: 429 } ); } // ... password validation ... recordFail(ip); } ``` Because `X-Forwarded-For` is accepted directly from the