Allen Bradley PLC5 Systems Detection Scanner

Allen Bradley PLC5 systems are programmable logic controllers used in industrial automation for manufacturing, energy, and infrastructure. They communicate via CSPV4 or AB/Ethernet protocols, often integrated with software like RSLinx for monitoring and control. These devices are critical for real-time operations in sectors such as automotive, oil and gas, and water treatment.

The vulnerability arises from the lack of authentication in CSPV4 protocol responses, allowing any network actor to query and identify PLC5 systems. This detection method exploits the trust-based nature of industrial protocols, where devices respond to identity requests without verifying the sender, exposing system inventory to potential attackers.

Technically, the scanner sends a crafted CSPV4 packet to TCP port 2222. If the target responds with a session ID matching expected patterns, the system is confirmed as an Allen Bradley PLC5. The scanner uses binary packing to structure the request and unpacks the response to validate compliance, effectively fingerprinting the device.

Exploitation could lead to unauthorized network mapping, enabling targeted attacks such as denial of service, command injection, or data manipulation. In industrial environments, this can cause production downtime, safety hazards, or financial losses. Identifying these systems is the first step to securing them against advanced persistent threats.