Modicon Modbus/TCP Programming Function Code Access

medium Nessus Plugin ID 23819

Synopsis

A Modicon PLC Modbus TCP interface is listening on TCP port 502 and is accessible via proprietary function code 126.

Description

A Modicon PLC Modbus TCP interface is listening on TCP port 502 and is accessible via proprietary function code 126. An attacker that is able to gain network access to this device can reprogram PLC logic or otherwise impact the integrity of the physical process.

Solution

Restrict incoming traffic on this port to authorized Modbus TCP clients.

Plugin Details

Severity: Medium

ID: 23819

File Name: scada_modbus_modicon_program.nbin

Version: 1.23

Type: remote

Family: SCADA

Published: 12/11/2006

Updated: 3/19/2024

Supported Sensors: Nessus

Risk Information

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:P

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L