CVE-2020-7538 : Security Advisory and Response

A CWE-754 vulnerability exists in PLC Simulator on EcoStruxure Control Expert (now Unity Pro) that could lead to a crash when receiving a specially crafted request over Modbus.

Understanding CVE-2020-7538

This CVE involves an Improper Check for Unusual or Exceptional Conditions vulnerability in the PLC Simulator on EcoStruxure Control Expert (Unity Pro).

What is CVE-2020-7538?

This CVE identifies a flaw in the PLC Simulator on EcoStruxure Control Expert software that could result in a crash when a specific type of request is received over Modbus.

The Impact of CVE-2020-7538

The vulnerability could be exploited by an attacker to cause a denial of service by crashing the PLC simulator within the affected software.

Technical Details of CVE-2020-7538

This section provides more in-depth technical information about the CVE.

Vulnerability Description

The vulnerability is categorized as CWE-754, indicating an improper check for unusual or exceptional conditions within the software.

Affected Systems and Versions

Product: PLC Simulator on EcoStruxure Control Expert (Unity Pro)
Vendor: n/a
Versions: All versions of the PLC Simulator on EcoStruxure Control Expert

Exploitation Mechanism

The vulnerability can be exploited by sending a specially crafted request over Modbus to trigger a crash in the PLC simulator.

Mitigation and Prevention

Protecting systems from CVE-2020-7538 requires immediate action and long-term security practices.

Immediate Steps to Take

Apply vendor-supplied patches or updates promptly.
Monitor network traffic for any suspicious activity related to Modbus communication.

Long-Term Security Practices

Regularly update and patch all software and firmware to prevent vulnerabilities.
Implement network segmentation to limit the impact of potential attacks.

Patching and Updates

Ensure that the PLC Simulator on EcoStruxure Control Expert (Unity Pro) is updated with the latest patches and security fixes to mitigate the risk of exploitation.