Improper Validation of Specified Quantity in Input vulnerability in Mitsubishi Electric MELSEC iQ-R Series R08PCPU, R16PCPU, R32PCPU, and R120PCPU allows an unauthenticated attacker to read device data or part of a control program from the affected product, write device data in the affected product, or cause a denial of service (DoS) condition on the affected product by sending a specially crafted packet containing a specific command to the affected product.