Schneider-electric » Modbus Firmware : Security Vulnerabilities, CVEs,

An Authentication Bypass by Capture-Replay issue was discovered in Schneider Electric Modicon Modbus Protocol. Sensitive information is transmitted in cleartext in the Modicon Modbus protocol, which may allow an attacker to replay the following commands: run, stop, upload, and download.

A Violation of Secure Design Principles issue was discovered in Schneider Electric Modicon Modbus Protocol. The Modicon Modbus protocol has a session-related weakness making it susceptible to brute-force attacks.