9Router has a Login Brute-Force Lockout Bypass via Spoofable X-9r-Real-Ip Header

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

9Router is an AI router & token saver. Prior to 0.5.6, 9Router deployments that allow requests to reach Next.js without the sanitizing custom-server.js wrapper use the client-supplied X-9r-Real-Ip value as the bucket key in getClientIp, checkLock, and recordFail in src/lib/auth/loginLimiter.js for POST /api/auth/login. A remote unauthenticated attacker can rotate the header on every password guess so each request uses a new failed-attempt bucket and the five-attempt progressive lockout never returns HTTP 429. This permits unthrottled password guessing against the dashboard login and can lead to an administrative session if the password is recovered. This issue is fixed in version 0.5.6.

[ Fixes ]Fixes and patches

• 9router 0.5.8Fixed version · GitHub Advisories · npm package 9router: upgrade to 0.5.8 or later (affected <= 0.5.4)

[ Packages ]Affected open-source packages

• 9router npmAffected <= 0.5.4 · fixed in 0.5.8 · GHSA-32gc-64m7-hj7v

[ References ]References

• github.com/decolua/9router/security/advisories/GHSA-32gc-64m7-hj7vx_refsource_CONFIRM
• github.com/decolua/9router/commit/efd20be8d81ef2e256a7037f3aa78e6b567b5fd3x_refsource_MISC
• github.com/decolua/9router/releases/tag/v0.5.6x_refsource_MISC