CVE-2021-37205 : What You Need to Know

A vulnerability has been identified in SIMATIC Drive Controller family, SIMATIC ET 200SP Open Controller CPU 1515SP PC2, SIMATIC S7-1200 CPU family, SIMATIC S7-1500 CPU family, SIMATIC S7-1500 Software Controller, SIMATIC S7-PLCSIM Advanced, SIPLUS TIM 1531 IRC, TIM 1531 IRC. An unauthenticated attacker could cause a denial-of-service condition in a PLC when sending specially prepared packets over port 102/tcp.

Understanding CVE-2021-37205

This section provides detailed insights into the CVE-2021-37205 vulnerability.

What is CVE-2021-37205?

The vulnerability affects various Siemens products including SIMATIC Drive Controller family, SIMATIC ET 200SP Open Controller CPU 1515SP PC2, SIMATIC S7-1200 CPU family, SIMATIC S7-1500 CPU family, SIMATIC S7-1500 Software Controller, SIMATIC S7-PLCSIM Advanced, SIPLUS TIM 1531 IRC, and TIM 1531 IRC. It allows an unauthenticated attacker to trigger a denial-of-service condition by sending specially crafted packets to port 102/tcp.

The Impact of CVE-2021-37205

The vulnerability could lead to a denial-of-service condition in the affected PLC devices, requiring a restart to restore normal operations. This can potentially disrupt industrial processes and control systems.

Technical Details of CVE-2021-37205

This section covers the technical aspects of the CVE-2021-37205 vulnerability.

Vulnerability Description

CVE-2021-37205 involves a missing release of memory after the effective lifetime, which can be exploited by an unauthenticated attacker to disrupt PLC operations.

Affected Systems and Versions

The vulnerability impacts multiple versions of Siemens products, including SIMATIC Drive Controller family, SIMATIC ET 200SP Open Controller CPU 1515SP PC2, SIMATIC S7-1200 CPU family, SIMATIC S7-1500 CPU family, SIMATIC S7-1500 Software Controller, SIMATIC S7-PLCSIM Advanced, SIPLUS TIM 1531 IRC, and TIM 1531 IRC.

Exploitation Mechanism

An unauthenticated attacker can exploit CVE-2021-37205 by sending specially crafted packets over port 102/tcp, leading to a denial-of-service condition in the PLC devices.

Mitigation and Prevention

This section outlines the steps to mitigate and prevent the exploitation of CVE-2021-37205.

Immediate Steps to Take

Immediately apply vendor-released patches and updates to the affected Siemens products to address the vulnerability and prevent potential exploitation.

Long-Term Security Practices

Implement network segmentation, access controls, and monitoring mechanisms to enhance the overall security posture of industrial control systems.

Patching and Updates

Regularly check for security advisories from Siemens and apply patches and updates promptly to protect against known vulnerabilities.