Port 1602: Inspect — When inspection became exposure

Port 1602 is officially registered with IANA for a service called "inspect"—likely intended for network inspection or monitoring functions. But the real story of this port isn't about its official designation. It's about what happened when industrial automation systems started using ports in this range for debugging.

The Official Assignment

Service: inspect
Port: 1602
Protocol: TCP and UDP
Range: Registered ports (1024-49151)

The "inspect" service name suggests network inspection, monitoring, or diagnostic functions. IANA's registry lists it, but provides no RFC, no specification, no detailed description. It's a placeholder—a name waiting for someone to give it meaning.

The Real-World Use: Industrial Automation Gone Wrong

In practice, port 1602 became associated with MINOVA's TTA (Tank Terminal Automation) software—industrial control systems used in tank farms, refineries, and critical infrastructure. The software used a cluster of ports in this range (1602, 1603, 1604, 1636) for debugging and remote management.¹

The problem? One of these debug ports (TCP 1604, closely related to 1602) exposed FTP credentials in plaintext. No authentication required. Just connect to the port, and the system would hand over production credentials.²

CVE-2025-7426: Critical Vulnerability

CVSSv4.0 Score: 9.3 (Critical)

An unprotected debug port disclosed FTP credentials in plaintext, allowing attackers with network access to:

• Retrieve sensitive production data without authentication
• Manipulate industrial processes
• Violate compliance requirements in critical infrastructure

All versions of MINOVA TTA up to 11.17.0 were affected.²

The fix? Upgrade to version 11.18.0 or higher, and immediately block ports 1602, 1603, 1604, and 1636 at perimeter and host-based firewalls.

The Gap Between Intent and Reality

Here's what's strange: IANA registered port 1602 for "inspect." Someone at MINOVA used ports in this range for debugging industrial systems. The name almost fits—inspection, debugging, monitoring—they're conceptually related.

But somewhere between the bureaucracy of port registration and the reality of industrial software development, security got lost. A port meant for inspection became a window into tank farms. A debug interface meant for engineers became an unauthenticated backdoor.

This is how vulnerabilities happen. Not through malice, but through the gap between what we intend and what we build.

Registered Ports: The Middle Ground

Port 1602 sits in the registered port range (1024-49151). These aren't the famous ports—not HTTP on 80 or HTTPS on 443. They're the middle tier: officially tracked by IANA but available for applications to claim.

The process is loose. Submit a form, describe your service, get a number. There's no enforcement. No one checks if you're actually using the port for what you claimed. And there's nothing stopping someone else from using the same port for something completely different.

That's why "inspect" and "TTA debug interface" can coexist on the same port number. The registry is more suggestion than law.

Security Implications

If you find port 1602 open on your network:

Ask what's listening. Use netstat, lsof, or ss to identify the process:

# Linux/macOS
sudo lsof -i :1602
sudo netstat -tulpn | grep 1602
sudo ss -tulpn | grep 1602

# Windows
netstat -ano | findstr :1602

If it's MINOVA TTA: Check your version immediately. If you're running anything before 11.18.0, you have a critical vulnerability. Upgrade now. Block the ports at your firewall. This isn't theoretical—it's a 9.3 CVSS score for a reason.

If it's something else: Question why it's there. Registered ports should have a purpose. If you don't know what's using port 1602, find out. Unknown services are how breaches start.

If nothing's listening: You're fine. Closed ports don't expose anything.

Why Unassigned Ports Matter

Even though port 1602 has an official name, its real meaning came from how it was used. That's true for most registered ports. The registry is a phone book, not a constitution. Applications use whatever ports they want, and we deal with the consequences.

The lesson isn't "don't use registered ports." The lesson is: every open port is a question your network is asking the Internet. Make sure you know what answer you're expecting.

How to Check What's Using Port 1602

# Check if anything is listening
nmap -p 1602 localhost

# See what process owns it
sudo lsof -i :1602

# Check firewall rules
sudo iptables -L -n | grep 1602  # Linux
netsh advfirewall firewall show rule name=all | findstr 1602  # Windows

If you find MINOVA TTA or any industrial control system using this port, treat it as critical infrastructure. Lock it down. Audit it. Don't assume the vendor got security right.