Overview
In the world of industrial automation and digitization, security vulnerabilities pose a significant threat to the integrity of systems and data. A recent vulnerability, CVE-2025-40743, affects a range of SINUMERIK systems, which are widely used in the manufacturing industry. This vulnerability lies in the improper validation of authentication for the Virtual Network Computing (VNC) access service, thereby permitting unauthorized remote access with insufficient password verification. This breach could potentially compromise system confidentiality, integrity, or availability, making it a matter of high concern for all organizations employing the affected SINUMERIK systems.
Vulnerability Summary
CVE ID: CVE-2025-40743
Severity: High (CVSS 8.3)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Unauthorized remote system access leading to potential system compromise or data leakage
Affected Products
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Product | Affected Versions
SINUMERIK 828D PPU.4 | All versions < V4.95 SP5 SINUMERIK 828D PPU.5 | All versions < V5.25 SP1 SINUMERIK 840D sl | All versions < V4.95 SP5 SINUMERIK MC | All versions < V1.25 SP1 SINUMERIK MC V1.15 | All versions < V1.15 SP5 SINUMERIK ONE | All versions < V6.25 SP1 SINUMERIK ONE V6.15 | All versions < V6.15 SP5 How the Exploit Works
This vulnerability exposes the VNC access service’s inherent weakness in the affected SINUMERIK systems. The application fails to correctly validate authentication, which allows an attacker to bypass the authentication process with improper or weak password verification. This loophole gives the attacker unauthorized remote access to the system, potentially compromising the system’s confidentiality, integrity, and availability.
Conceptual Example Code
While the specific code to exploit this vulnerability isn’t disclosed for security reasons, a conceptual example might resemble the following:
#!/bin/bash
# Connect to the VNC server
vncviewer target_ip:5901
# Enter weak or common password
password: admin123The bash script above demonstrates a simplistic example of how an attacker might attempt to gain unauthorized access by using a weak or commonly used password due to the insufficient password verification of the VNC service. This can lead to unauthorized remote access, enabling the attacker to potentially compromise the system or cause data leakage.
Remember, this conceptual example is not an actual exploit but a representation of how an attacker might approach exploiting the vulnerability.