Flowise Vulnerable to PII Disclosure on Unauthenticated Forgot Password Endpoint

Summary

The /api/v1/account/forgot-password endpoint returns the full user object including PII (id, name, email, status, timestamps) in the response body instead of a generic success message. This exposes sensitive user information to unauthenticated attackers who only need to know a valid email address.

Vulnerability Details

Field	Value
CWE	CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
Affected File	packages/server/src/enterprise/services/account.service.ts (lines 517-545)
Endpoint	POST /api/v1/account/forgot-password
Authentication	None required
CVSS 3.1	3.7 (Low)

Root Cause

In account.service.ts, the forgotPassword method returns the sanitized user object instead of a simple success acknowledgment:

public async forgotPassword(data: AccountDTO) {
    // ...
    const user = await this.userService.readUserByEmail(data.user.email, queryRunner)
    if (!user) throw new InternalFlowiseError(StatusCodes.NOT_FOUND, UserErrorMessage.USER_NOT_FOUND)

    data.user = user
    // ... password reset logic ...

    return sanitizeUser(data.user)  // Returns user object with PII
}

The sanitizeUser function only removes sensitive authentication fields:

export function sanitizeUser(user: Partial<User>) {
    delete user.credential    // password hash
    delete user.tempToken     // reset token
    delete user.tokenExpiry

    return user  // Still contains: id, name, email, status, createdDate, updatedDate
}

Impact

An unauthenticated attacker can:

1. Harvest PII: Collect user IDs, full names, and account metadata
2. Profile users: Determine account creation dates and activity patterns
3. Enumerate accounts: Confirm email existence and gather associated data
4. Enable further attacks: Use harvested data for social engineering or targeted phishing

Exploitation

curl -X POST "https://cloud.flowiseai.com/api/v1/account/forgot-password" \
  -H "Content-Type: application/json" \
  -d '{"user":{"email":"[email protected]"}}'

<img width="1582" height="791" alt="screenshot" src="https://github.com/user-attachments/assets/9880f037-6e21-41d7-a7c8-7057c6775b50" />