Rewterz Threat Advisory – ICS: Mitsubishi Electric FA Engineering Software and GX Works2

Severity

High

Analysis Summary

CVE-2021-20608

If an attacker tampers with a program file in a Mitsubishi Electric PLC by sending malicious crafted packets to the PLC, reading the program file into GX Works2, the engineering software incorrectly handles a length field that is inconsistent with the actual length of the associated data, which could result in a denial-of-service condition in the software.

CVE-2021-20607

When a valid user opens a malicious project file specially crafted by an attacker, the product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.

CVE-2021-20606

When a valid user opens a malicious project file specially crafted by an attacker, the software reads data outside of the intended buffer, allowing an attacker to potentially cause a denial-of-service condition in the software.

Impact

• Denial of Service

Affected Vendors

• Mitsubishi Electric

Affected Products

• GX Works2: Versions 1.606G and prior
• MELSOFT Navigator: All versions
• EZSockdet: All versions

Remediation

Refer to CISA Advisory for the patch, upgrade, or suggested workaround information.