Mitsubishi Electric MELSEC C Controller Module and MELIPC Series MI5000 MELSEC-Q Series C Controller Module(Q24DHCCPU-V, Q24DHCCPU-VG User Ethernet port (CH1, CH2): First 5 digits of serial number 21121 or before), MELSEC iQ-R Series C Controller Module / C Intelligent Function Module(R12CCPU-V Ethernet port (CH1, CH2): First 2 digits of serial number 11 or before, and RD55UP06-V Ethernet port: First 2 digits of serial number 08 or before), and MELIPC Series MI5000(MI5122-VW Ethernet port (CH1): First 2 digits of serial number 03 or before, or the firmware version 03 or before) allow remote attackers to cause a denial of service and/or malware being executed via unspecified vectors.