Improper neutralization of argument delimiters in a command ('Argument Injection') vulnerability in TCP/IP function included in the firmware of MELSEC iQ-R series (RJ71EIP91 EtherNet/IP Network Interface Module First 2 digits of serial number are '02' or before, RJ71PN92 PROFINET IO Controller Module First 2 digits of serial number are '01' or before, RD81DL96 High Speed Data Logger Module First 2 digits of serial number are '08' or before, RD81MES96N MES Interface Module First 2 digits of serial number are '04' or before, and RD81OPC96 OPC UA Server Module First 2 digits of serial number are '04' or before) allows unauthenticated attackers on adjacent network to stop the network functions of the products via a specially crafted packet.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-5657
• https://jvn.jp/vu/JVNVU92513419/index.html
• https://www.mitsubishielectric.co.jp/psirt/vulnerability/pdf/2020-012.pdf
• https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2020-012_en.pdf