OpenBMB StaffDeck through 0.5.6 Authentication Bypass via Hard-Coded Session Secret

OpenBMB StaffDeck through 0.5.6 contains an authentication bypass vulnerability that allows unauthenticated attackers to forge administrator session tokens using the hard-coded default app_secret. Attackers can sign an HMAC-SHA256 token for the seeded 'admin' user in 'tenant_demo' to gain full tenant administration, including stored model and channel credentials.