CVE-2021-20598 : Security Advisory and Response

A detailed overview of the Overly Restrictive Account Lockout Mechanism vulnerability found in Mitsubishi Electric MELSEC iQ-R series CPU modules.

Understanding CVE-2021-20598

This CVE discloses an account lockout vulnerability in Mitsubishi Electric MELSEC iQ-R series CPU modules, potentially enabling remote attackers to lock out valid users.

What is CVE-2021-20598?

The vulnerability in MELSEC iQ-R series CPU modules allows unauthenticated remote attackers to lock out legitimate users by repeatedly attempting login with incorrect credentials.

The Impact of CVE-2021-20598

The impact of this vulnerability is severe as it jeopardizes the availability of the affected systems and services by denying access to authorized users.

Technical Details of CVE-2021-20598

Exploring the vulnerability, its affected systems, and exploitation mechanism.

Vulnerability Description

The flaw arises from an overly restrictive account lockout mechanism in the CPU modules, making it susceptible to being locked out through brute-force attacks.

Affected Systems and Versions

The vulnerability affects all versions of MELSEC iQ-R series CPU modules R08/16/32/120SFCPU and R08/16/32/120PSFCPU.

Exploitation Mechanism

Remote unauthenticated attackers exploit the vulnerability by continuously inputting incorrect passwords to lock out authorized users.

Mitigation and Prevention

Guidelines to address and prevent exploitation of CVE-2021-20598.

Immediate Steps to Take

Immediate actions involve monitoring and limiting login attempts, implementing multi-factor authentication, and monitoring account lockouts.

Long-Term Security Practices

Establishing robust security protocols, conducting regular security assessments, and ensuring timely software updates to mitigate similar vulnerabilities.

Patching and Updates

Vendor-provided patches or updates should be promptly applied to eliminate the vulnerability and enhance system security.