CVE-2019-13555 : What You Need to Know

Mitsubishi Electric MELSEC-Q and MELSEC-L Series CPUs are vulnerable to a denial-of-service attack through the FTP service.

Understanding CVE-2019-13555

This CVE identifies a vulnerability in specific Mitsubishi Electric CPU modules that can be exploited by a remote attacker to disrupt the FTP service, leading to a denial-of-service condition.

What is CVE-2019-13555?

The vulnerability in Mitsubishi Electric MELSEC-Q and MELSEC-L Series CPUs allows a remote attacker to trigger a denial-of-service situation by manipulating the timing of their connection to the FTP server on the affected CPU modules.

The Impact of CVE-2019-13555

The vulnerability can result in a denial-of-service condition in the FTP service of the impacted Mitsubishi Electric CPU modules, affecting the availability and functionality of the systems.

Technical Details of CVE-2019-13555

This section provides detailed technical insights into the vulnerability.

Vulnerability Description

The vulnerability in the Mitsubishi Electric MELSEC-Q and MELSEC-L Series CPUs enables a remote attacker to disrupt the FTP service, causing a denial-of-service condition based on the timing of their connection to the FTP server.

Affected Systems and Versions

Mitsubishi Electric MELSEC-Q Series CPUs: Q03/04/06/13/26UDVCPU, Q04/06/13/26UDPVCPU, Q03UDECPU, Q04/06/10/13/20/26/50/100UDEHCPU
Mitsubishi Electric MELSEC-L Series CPUs: L02/06/26CPU, L26CPU-BT, L02/06/26CPU-P, L26CPU-PBT, L02/06/26CPU-CM, L26CPU-BT-CM

Exploitation Mechanism

The vulnerability is exploited by a remote attacker manipulating the timing of their connection to the FTP server on the affected Mitsubishi Electric CPU modules.

Mitigation and Prevention

Protecting systems from CVE-2019-13555 requires immediate actions and long-term security measures.

Immediate Steps to Take

Implement network segmentation to isolate critical systems from potential attackers.
Monitor network traffic for any suspicious activity targeting the FTP service.
Apply firewall rules to restrict unauthorized access to the FTP service.

Long-Term Security Practices

Regularly update and patch the firmware of Mitsubishi Electric MELSEC-Q and MELSEC-L Series CPUs.
Conduct security assessments and penetration testing to identify and address vulnerabilities proactively.
Educate system administrators and users on best practices for secure system configurations.

Patching and Updates

Stay informed about security advisories and updates from Mitsubishi Electric regarding CVE-2019-13555.
Apply patches and firmware updates provided by the vendor to mitigate the vulnerability effectively.