CVE-2021-20610 : What You Need to Know

A vulnerability in Mitsubishi Electric MELSEC devices allows a remote attacker to trigger a denial-of-service (DoS) attack by exploiting an improper handling of length parameter inconsistency. This article provides an overview of the CVE-2021-20610 vulnerability, its impact, affected systems, and mitigation steps.

Understanding CVE-2021-20610

This section delves into the details of the CVE-2021-20610 vulnerability affecting Mitsubishi Electric MELSEC devices.

What is CVE-2021-20610?

The CVE-2021-20610 vulnerability involves improper handling of length parameter inconsistency in various Mitsubishi Electric MELSEC iQ-R, MELSEC Q, MELSEC L Series, and MELIPC Series devices. It allows a remote unauthenticated attacker to execute a DoS attack by sending specially crafted packets.

The Impact of CVE-2021-20610

The primary impact of CVE-2021-20610 is the denial-of-service (DoS) condition triggered by the remote attacker. This can potentially disrupt the normal operation of affected devices, requiring a system reset for recovery.

Technical Details of CVE-2021-20610

This section provides technical insights into the vulnerability, including its description, affected systems, and exploitation mechanism.

Vulnerability Description

The vulnerability lies in the improper handling of length parameter inconsistency in the firmware and operating system software of multiple Mitsubishi Electric MELSEC devices. A remote attacker can exploit this flaw to launch a DoS attack.

Affected Systems and Versions

Various models from the MELSEC iQ-R, Q, L Series, and MELIPC Series are impacted by CVE-2021-20610. Specific firmware versions and serial numbers are vulnerable to the attack.

Exploitation Mechanism

By sending specially crafted packets to the affected devices, a remote unauthenticated attacker can exploit the length parameter inconsistency vulnerability to cause a DoS condition.

Mitigation and Prevention

This section outlines steps to mitigate the CVE-2021-20610 vulnerability and prevent potential exploitation.

Immediate Steps to Take

Update the firmware or operating system software to non-vulnerable versions provided by Mitsubishi Electric Corporation.
Implement network security measures to restrict unauthorized access to the devices.

Long-Term Security Practices

Regularly monitor vendor security advisories for updates on mitigations and patches.
Conduct security assessments and penetration testing to identify and address vulnerabilities proactively.

Patching and Updates

Apply patches and security updates released by Mitsubishi Electric Corporation promptly to address the CVE-2021-20610 vulnerability and enhance the security posture of the affected devices.