Improper Input Validation vulnerability in Mitsubishi Electric MELSEC-Q Series QJ71E71-100 first 5 digits of serial number "24061" or prior, Mitsubishi Electric MELSEC-L series LJ71E71-100 first 5 digits of serial number "24061" or prior and Mitsubishi Electric MELSEC iQ-R Series RD81MES96N firmware version "08" or prior allows a remote unauthenticated attacker to cause a denial of service (DoS) condition or execute malicious code on the target products by sending specially crafted packets.