CVE-2025-27540: Severe SQL Injection Vulnerability in TeleControl Server Basic

Overview

In an era where cybersecurity risks are ever evolving and increasingly sophisticated, it is crucial to stay up-to-date with the latest vulnerabilities and patches. This post provides a detailed analysis of a recently discovered vulnerability, CVE-2025-27540, affecting all versions of TeleControl Server Basic before V3.1.2.2. This vulnerability is particularly concerning due to the potential for an unauthenticated remote attacker to bypass authorization controls, enabling them to read from and write to the application’s database and execute code with “NT AUTHORITYNetworkService” permissions. The impacts of this vulnerability could be system compromise or data leakage, making it a high priority for organizations that use TeleControl Server Basic.

Vulnerability Summary

CVE ID: CVE-2025-27540
Severity: Critical 9.8 (CVSS v3.0)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

TeleControl Server Basic | All versions < V3.1.2.2 How the Exploit Works

The vulnerability lies in the ‘Authenticate’ method of the TeleControl Server Basic application. An unauthenticated remote attacker can send specially crafted SQL statements, which could exploit the vulnerability to execute arbitrary code on the system. This happens due to improper sanitization of user input in the authentication process. A successful attack could lead to a complete system compromise with the attacker gaining the ability to read and write to the application’s database and execute code with “NT AUTHORITYNetworkService” permissions.

Conceptual Example Code

Here is a conceptual example of how the vulnerability might be exploited:

POST /Authenticate HTTP/1.1
Host: vulnerable_server:8000
Content-Type: application/json
{ "username": "admin'; DROP TABLE users; --", "password": "password" }

In this example, the attacker sends a malicious SQL statement via the username parameter, which could potentially delete the entire users table from the database. This example demonstrates the severity of the risk, but the actual impact could be far more extensive, based on the SQL commands executed by the attacker.
Remember, this is a conceptual example and real-world attacks might be more sophisticated and harder to detect. Thus, it is crucial to apply the vendor-provided patch or utilize a Web Application Firewall (WAF) or Intrusion Detection System (IDS) as temporary mitigation.