Incorrect Implementation of Authentication Algorithm in Mitsubishi Electric Air Conditioning System/Centralized Controllers (G-50A Ver.2.50 to Ver. 3.35, GB-50A Ver.2.50 to Ver. 3.35, AG-150A-A Ver.3.20 and prior, AG-150A-J Ver.3.20 and prior, GB-50ADA-A Ver.3.20 and prior, GB-50ADA-J Ver.3.20 and prior, EB-50GU-A Ver 7.09 and prior, EB-50GU-J Ver 7.09 and prior, AE-200A Ver 7.93 and prior, AE-200E Ver 7.93 and prior, AE-50A Ver 7.93 and prior, AE-50E Ver 7.93 and prior, EW-50A Ver 7.93 and prior, EW-50E Ver 7.93 and prior, TE-200A Ver 7.93 and prior, TE-50A Ver 7.93 and prior, TW-50A Ver 7.93 and prior, CMS-RMD-J Ver.1.30 and prior) and Air Conditioning System/Expansion Controllers (PAC-YG50ECA Ver.2.20 and prior) allows a remote authenticated attacker to impersonate administrators to disclose configuration information of the air conditioning system and tamper information (e.g. operation information and configuration of air conditioning system) by exploiting this vulnerability.