CVE-2025-40736: Unauthorized Administrative Credentials Modification in SINEC NMS

Overview

CVE-2025-40736 is a critical vulnerability discovered in SINEC NMS, a popular network management solution. This vulnerability directly affects the security of all versions below the V4.0 of SINEC NMS. The vulnerability stems from an exposed endpoint in the application that allows for unauthorized changes to administrative credentials, putting the entire application and associated networks at risk. This flaw could potentially give an unauthenticated attacker the ability to reset the superadmin password and gain complete control of the application, leading to system compromise or data leakage.

Vulnerability Summary

CVE ID: CVE-2025-40736
Severity: Critical (9.8 CVSS score)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Unauthorized modification of administrative credentials leading to full system compromise

Affected Products

Product | Affected Versions

SINEC NMS | All versions < V4.0 How the Exploit Works

The vulnerability, CVE-2025-40736, allows an attacker to manipulate the exposed endpoint that handles administrative credentials in the application. By exploiting this endpoint, an attacker can send specially crafted requests to modify the superadmin password. As the endpoint does not sufficiently verify the authenticity of the requests, the attacker can successfully change the password and gain full control of the application without any legitimate administrative privileges.

Conceptual Example Code

Here’s a conceptual example of how an attacker might exploit the vulnerability. This is a hypothetical HTTP request to the vulnerable endpoint, changing the superadmin password:

POST /admin/credentials/reset HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "user": "superadmin", "new_password": "malicious_password" }

This request resets the superadmin password, which, when successful, provides the attacker full control of the system, leading to potential data leakage or system compromise.

Mitigation Guidance

The best way to mitigate this vulnerability is to apply the vendor-provided patch. This will properly secure the endpoint and prevent unauthorized modification of administrative credentials. For immediate temporary mitigation, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can help to filter out malicious requests. However, these measures should be seen as temporary fixes and not a replacement for the vendor’s patch.