An Insecure Direct Object Reference (IDOR) vulnerability exists at the GET /api/v1/organization/customer-default-source endpoint. This flaw allows an authenticated attacker to bypass authorization checks and retrieve sensitive payment and profile information of other customers by manipulating the customerId parameter. The exposed data includes email addresses, account balances, currency types, and internal billing configurations.
The application fails to implement proper object-level access control. While the endpoint requires a valid session/token, it does not verify if the requesting user has the authority to access the specific customerId provided in the query string.
When a request is made to: GET /api/v1/organization/customer-default-source?customerId=cus_XXXX
The server processes the request based solely on the existence of a valid session, returning the data associated with the ID regardless of the data owner's identity. Since customer IDs follow a predictable pattern (Stripe-formatted cus_...), an attacker could potentially enumerate these IDs to scrape customer data.
To reproduce the vulnerability, follow these steps:
Log in to your account at cloud.flowiseai.com.
Capture a request to the payment source endpoint using a proxy tool (e.g., Burp Suite).
Change the customerId parameter in the URL to a target user's ID (e.g., cus_U9ajkQvu0e67uH).
Execute the request:
GET /api/v1/organization/customer-default-source?customerId=cus_U9ajkQvu0e67uH HTTP/2
Host: cloud.flowiseai.com
Cookie: [YOUR_AUTHENTICATED_COOKIES]
...
Response:
{
"id": "cus_U9ajkQvu0e67uH",
"object": "customer",
"email": "[email protected]",
"balance": 0,
"currency": "usd",
"invoice_settings": {
"custom_fields": null,
"default_payment_method": null
},
"livemode": true
...
}
The server returns a 200 OK status with the private data of the target customer.
Vulnerability Type: Broken Access Control (IDOR).
Impacted Parties: All registered users and organizations on the FlowiseAI Cloud platform.
Consequences: * Data Privacy Breach: Exposure of Personally Identifiable Information (PII) such as email addresses.
Financial Information Leakage: Disclosure of account balances, currency settings, and invoice metadata.
Compliance Risk: Potential violation of data protection regulations (e.g., GDPR) due to unauthorized access to user billing profiles.
| Software | Affected versions |
|---|---|
flowise
|
< 3.1.3 |
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
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