Affected: Schneider Electric Modicon M340 CPU (part numbers BMXP34*), Schneider Electric Modicon MC80 (part numbers BMKC80), Schneider Electric Modicon Momentum Unity M1E Processor (171CBU*), schneider-electric modicon_m340_bmxp341000, schneider-electric modicon_mc80_bmkc8020301, schneider-electric modicon_momentum_unity_m1e_processor

CWE-290: Authentication Bypass by Spoofing vulnerability exists that could cause a denial of service and loss of confidentiality and integrity of controllers when conducting a Man-In-The-Middle attack between the controller and the engineering workstation while a valid user is establishing a communication session. This vulnerability is inherent to Diffie Hellman algorithm which does not protect against Man-In-The-Middle attacks.