Missing Password Field Masking vulnerability in Mitsubishi Electric Corporation EtherNet/IP configuration tools SW1DNN-EIPCT-BD and SW1DNN-EIPCTFX5-BD allows a remote unauthenticated attacker to know the password for MELSEC iQ-R Series EtherNet/IP module RJ71EIP91 and MELSEC iQ-F Series EtherNet/IP module FX5-ENET/IP. This vulnerability results in authentication bypass vulnerability, which allows the attacker to access MELSEC iQ-R Series EtherNet/IP module RJ71EIP91 and MELSEC iQ-F Series EtherNet/IP module FX5-ENET/IP via FTP.