A CWE-119 Buffer Errors vulnerability exists in Modicon M580 CPU - BMEP582040, all versions before V2.90, and Modicon Ethernet Module BMENOC0301, all versions before V2.16, which could cause denial of service on the FTP service of the controller or the Ethernet BMENOC module when it receives a FTP CWD command with a data length greater than 1020 bytes. A power cycle is then needed to reactivate the FTP service.