Uncontrolled resource consumption vulnerability in MELSEC iQ-R Series modules (R00/01/02CPU firmware version '19' and earlier, R04/08/16/32/120 (EN) CPU firmware version '51' and earlier, R08/16/32/120SFCPU firmware version '22' and earlier, R08/16/32/120PCPU firmware version '25' and earlier, R08/16/32/120PSFCPU firmware version '06' and earlier, RJ71EN71 firmware version '47' and earlier, RJ71GF11-T2 firmware version '47' and earlier, RJ72GF15-T2 firmware version '07' and earlier, RJ71GP21-SX firmware version '47' and earlier, RJ71GP21S-SX firmware version '47' and earlier, and RJ71GN11-T2 firmware version '11' and earlier) allows a remote unauthenticated attacker to cause an error in a CPU unit and cause a denial-of-service (DoS) condition in execution of the program and its communication, or to cause a denial-of-service (DoS) condition in communication via the unit by receiving a specially crafted SLMP packet
https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2020-016_en.pdf
https://www.mitsubishielectric.co.jp/psirt/vulnerability/pdf/2020-016.pdf