CVE-2018-11451 Explained : Impact and Mitigation

A security vulnerability has been discovered in various firmware variants, including IEC 61850, PROFINET IO, Modbus TCP, DNP3 TCP, and IEC104, for the EN100 Ethernet module. This vulnerability affects all versions prior to V4.33 for IEC 61850, all versions for PROFINET IO and Modbus TCP, and all versions prior to V1.22 for IEC104. It also affects SIPROTEC 5 relays with CPU variants CP300 and CP100, as well as their respective Ethernet communication modules, all versions prior to V7.80. Additionally, it affects SIPROTEC 5 relays with CPU variants CP200 and their respective Ethernet communication modules, all versions prior to V7.58. Exploiting this vulnerability involves sending specially crafted packets to port 102/tcp, which can lead to a denial-of-service situation in the affected products. To restore the functionality of the EN100 module in the affected devices, a manual restart is required. Successful exploitation requires an attacker to have network access and send multiple packets to the affected products or modules. The IEC 61850-MMS communication must be activated on the affected products or modules as a precondition for the vulnerability to be exploited. No user interaction or privileges are necessary to exploit this vulnerability. If successfully exploited, the vulnerability can compromise the availability of the system by causing a Denial-of-Service condition in the network functionality of the affected device. As of the publication of this advisory, there have been no known instances of public exploitation of this security vulnerability.

Understanding CVE-2018-11451

This CVE-2018-11451 vulnerability affects various firmware variants and SIPROTEC 5 relays with specific CPU variants and Ethernet communication modules.

What is CVE-2018-11451?

CVE-2018-11451 is a security vulnerability found in multiple firmware variants and relay devices manufactured by Siemens AG.

The Impact of CVE-2018-11451

The vulnerability can lead to a denial-of-service condition in the affected products and compromise system availability.
Successful exploitation requires network access and can be triggered by sending crafted packets to specific ports.

Technical Details of CVE-2018-11451

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability allows attackers to cause a denial-of-service condition by sending specially crafted packets to port 102/tcp.

Affected Systems and Versions

Firmware variant IEC 61850 for EN100 Ethernet module: All versions < V4.33
Firmware variant PROFINET IO for EN100 Ethernet module: All versions
Firmware variant Modbus TCP for EN100 Ethernet module: All versions
Firmware variant DNP3 TCP for EN100 Ethernet module: All versions
Firmware variant IEC104 for EN100 Ethernet module: All versions < V1.22
SIPROTEC 5 relays with CPU variants CP300 and CP100 and the respective Ethernet communication modules: All versions < V7.80
SIPROTEC 5 relays with CPU variants CP200 and the respective Ethernet communication modules: All versions < V7.58

Exploitation Mechanism

Attackers need to send specially crafted packets to port 102/tcp to exploit the vulnerability.
Successful exploitation requires network access and multiple packet transmissions.
Activation of IEC 61850-MMS communication is a prerequisite for exploiting the vulnerability.

Mitigation and Prevention

Protecting systems from CVE-2018-11451 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply patches provided by Siemens AG to address the vulnerability.
Monitor network traffic for any suspicious activities targeting port 102/tcp.
Restrict network access to vulnerable devices to authorized personnel only.

Long-Term Security Practices

Regularly update firmware and security patches for all devices in the network.
Conduct regular security assessments and penetration testing to identify vulnerabilities.
Implement network segmentation to isolate critical devices from potential threats.

Patching and Updates

Siemens AG may release patches to fix the vulnerability; ensure timely installation of these patches to secure the affected systems.