IoT Telnet Shell (telnetshell)

This skill enables interaction with IoT device shells accessible via telnet for security testing and penetration testing operations. It supports unauthenticated shells, weak authentication testing, device enumeration, and post-exploitation activities.

Prerequisites

• Python 3 with pexpect library (pip install pexpect or sudo pacman -S python-pexpect)
• telnet client installed on the system (sudo pacman -S inetutils on Arch)
• Network access to the target device's telnet port

Recommended Approach: Telnet Helper Script

IMPORTANT: This skill includes a Python helper script (telnet_helper.py) that provides a clean, reliable interface for telnet communication. This is the RECOMMENDED method for interacting with IoT devices.

Default Session Logging

ALL commands run by Claude will be logged to /tmp/telnet_session.log by default.

To observe what Claude is doing in real-time:

# In a separate terminal, run:
tail -f /tmp/telnet_session.log

This allows you to watch all telnet I/O as it happens without interfering with the connection.

Why Use the Telnet Helper?

The helper script solves many problems with direct telnet usage:

• Clean output: Automatically removes command echoes, prompts, and ANSI codes
• Prompt detection: Automatically detects and waits for device prompts
• Timeout handling: Proper timeout management with no arbitrary sleeps
• Easy scripting: Simple command-line interface for single commands or batch operations
• Session logging: All I/O logged to /tmp/telnet_session.log for observation
• Reliable: No issues with TTY requirements or background processes
• JSON output: For programmatic parsing and tool chaining

Quick Start with Telnet Helper

Single Command:

python3 .claude/skills/telnetshell/telnet_helper.py --host 192.168.1.100 --command "uname -a"