Description

Unauthenticated Broken Access Control in Simple Payment <= 2.5.2 versions.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-28T16:18:30.590Z",
  "pubdate": "2026-08-28T16:18:30.590Z",
  "executiveSummary": "Simple Payment versions 2.5.2 and below are susceptible to an Unauthenticated Broken Access Control vulnerability. This security flaw allows unauthenticated remote attackers to bypass authorization mechanisms, potentially gaining unauthorized access to sensitive payment-related functions or data without valid credentials.\nThe vulnerability resides within the application's access control layer, which fails to verify user authentication status or privilege levels for specific endpoints or administrative interfaces. By interacting directly with these exposed functions, an attacker can execute unauthorized actions, manipulate transaction states, or retrieve private information intended only for privileged administrators.\nThe risk implication is critical, as the exposure of payment-related logic could lead to financial data breaches, unauthorized transaction processing, or unauthorized modification of system settings. Exploitation does not require prior knowledge of the target system or valid authentication, significantly lowering the barrier for entry for malicious actors. The attack is executable over the network, making any internet-facing deployment of Simple Payment highly vulnerable to exploitation.\nOrganizations relying on affected versions should prioritize immediate remediation to prevent unauthorized data exfiltration or system compromise.",
  "technicalDetails": "The vulnerability originates from a failure to enforce consistent authorization checks across the application's request handling pipeline. In Simple Payment versions 2.5.2 and earlier, specific application routes and controller actions are accessible to any HTTP request, regardless of the sender's identity. The root cause is the absence of an integrated middleware or authentication gatekeeper that validates session tokens or user roles prior to executing sensitive backend logic.\nThe attack flow commences when an unauthenticated actor identifies the specific URL endpoints or API methods associated with protected functionalities. Since the application fails to perform a request-level verification, an attacker can craft direct HTTP GET or POST requests to these targets. The application proceeds to process the request as if it originated from an authorized user, thereby exposing sensitive application states.\nTechnically, the issue is an Insecure Direct Object Reference (IDOR) combined with insufficient functional-level access control. When an attacker invokes these endpoints, the underlying code executes internal business logic—such as updating payment statuses, viewing transaction logs, or modifying configuration settings—without verifying if the active session is associated with an administrator account. This bypass occurs because the check is either entirely omitted or implemented incorrectly, relying on client-side security measures that can be trivially bypassed.\nPost-exploitation impact is severe. Because the vulnerability targets the payment gateway integration or management interface, an attacker could potentially inject malicious parameters into payment requests, facilitate transaction redirection, or gain visibility into historical customer payment metadata. The lack of authentication means that the attack can be fully automated via scripted requests. The vulnerability is persistent across all versions up to 2.5.2, indicating a systemic failure in the authorization architecture that necessitates a rigorous audit of all request handlers and the implementation of a centralized access control mechanism to ensure that every sensitive method mandates verified authentication and appropriate authorization roles."
}