GHSA-php6-83fg-gw3g: Flowise: brute-force auth grants full agent platform access

**Detection Method:** Kolega.dev Deep Code Scan | Attribute | Value | |---|---| | Severity | Medium | | CWE | CWE-522 (Insufficiently Protected Credentials) | | Location | packages/server/src/enterprise/controllers/account.controller.ts:128-135 | | Practical Exploitability | Medium | | Developer Approver | faizan@kolega.ai | ### Description The checkBasicAuth endpoint validates credentials in plaintext without rate limiting and with direct comparison. ### Affected Code ``` public async checkBasicAuth(req: Request, res: Response) { const { username, password } = req.body if (username === process.env.FLOWISE_USERNAME && password === process.env.FLOWISE_PASSWORD) { return res.json({ message: 'Authentication successful' }) ``` ### Evidence Credentials are sent in plaintext in request body and compared directly without hashing. No rate limiting prevents brute force attacks. The endpoint returns different messages for success/failure, enabling enumeration. ### Impact Credential brute-forcing - attackers can attempt unlimited username/password combinations against the basic auth system. Successful attacks grant access to the application. ### Recommendation 1) Implement rate limiting on this endpoint, 2) Use constant-time comparison to prevent timing attacks, 3) Consider using hashed comparison, 4) Return generic error messages, 5) Add logging for failed attempts. ### Notes The checkBasicAuth endpoint at line 128-135 has multiple security issues: (1) No rate limiting - the RateLimiterManager only applies to chatflow-specific endpoints, not auth endpoints. Attackers can perform unlimited brute force attempts. (2) Uses JavaScript === operator for comparison which is not constant-time, potentially enabling timing attacks. (3) Returns different messages for success ('Authentication successful') vs failure ('Authentication failed'), enabling credential enumeration. The endpoint compares plaintext credentials against environment variables FLOWISE_USERNAME and FLOWISE_PASSWORD. While this is basic auth for simpler deployments, the lack of rate limiting makes it actively exploitable for credential brute-forcing.

An attacker enumerates internet-exposed Flowise instances via Shodan or Censys, identifies the /api/v1/verify/auth endpoint, and launches an automated credential stuffing or dictionary attack using common defaults and leaked credential lists. The endpoint's distinct 'Authentication successful' vs 'Authentication failed' responses confirm valid credentials without triggering any lockout. Once authenticated, the attacker accesses the Flowise dashboard to harvest LLM API keys and database connection strings, inject malicious tool definitions into active agent workflows for persistence or data exfiltration, or pivot to connected backend services via the agent's configured tool integrations.