CVE-2020-5655 : What You Need to Know

A NULL pointer dereferences vulnerability in the TCP/IP function of MELSEC iQ-R series allows remote attackers to disrupt network functions.

Understanding CVE-2020-5655

This CVE involves a critical vulnerability in Mitsubishi Electric Corporation's MELSEC iQ-R series.

What is CVE-2020-5655?

This vulnerability results in a NULL pointer dereference in the firmware of MELSEC iQ-R series products, potentially leading to a denial of service attack by sending a specially crafted packet.

The Impact of CVE-2020-5655

The vulnerability allows remote unauthenticated attackers to halt network functions of affected products, posing a significant risk to operational continuity and system availability.

Technical Details of CVE-2020-5655

This section delves into the technical aspects of the CVE.

Vulnerability Description

The vulnerability arises from a NULL pointer dereference in the TCP/IP function of the affected MELSEC iQ-R series products.

Affected Systems and Versions

Product: MELSEC iQ-R series
Versions: RJ71EIP91 EtherNet/IP Network Interface Module (First 2 digits of serial number are '02' or before), RJ71PN92 PROFINET IO Controller Module (First 2 digits of serial number are '01' or before), RD81DL96 High Speed Data Logger Module (First 2 digits of serial number are '08' or before), RD81MES96N MES Interface Module (First 2 digits of serial number are '04' or before), and RD81OPC96 OPC UA Server Module (First 2 digits of serial number are '04' or before)

Exploitation Mechanism

The vulnerability can be exploited remotely by sending a specially crafted packet to the affected devices, triggering the NULL pointer dereference and disrupting network functions.

Mitigation and Prevention

Protecting systems from CVE-2020-5655 is crucial to maintain operational integrity and security.

Immediate Steps to Take

Apply patches and updates provided by Mitsubishi Electric Corporation promptly.
Implement network segmentation to limit exposure of vulnerable devices.
Monitor network traffic for any suspicious activity that may indicate exploitation attempts.

Long-Term Security Practices

Regularly update firmware and software to address known vulnerabilities.
Conduct security assessments and penetration testing to identify and remediate weaknesses.
Educate personnel on cybersecurity best practices to enhance overall security posture.

Patching and Updates

Stay informed about security advisories and updates from Mitsubishi Electric Corporation.
Follow recommended patching procedures to ensure the mitigation of CVE-2020-5655.