Oracle listener statistics

When you want to look for some random hacks, the first tool that comes to you mind would obviously be Nmap.

It's a very powerful tool for scanning a remote host for open ports.

I recently found an article about Nmap statistics when looking for open TNS Listeners.

Here is an extract of the article:

For experiment, I and my friends ran nmap with -iR 0 -p1521 options, meaning checking for open port 1521 on randomly generated IP addresses, infinitely.

Result: one working Oracle TNS Listener among nearly 69,000 random IP addresses.

Source: blogs.conus.info

Here is the detail of the experiment:

Top 3 operational systems:

1. 52% - Windows
2. 37% - Linux
3.   6% - Solaris

Oracle TNS Listener versions:

55% - 10.2

23% - 9.2

7% - 11.1

5% - 8.1

4% - 10.1

2% - 8.0

2% - 9.0

So I decided to run the test myself, and tried the Nmap command previously shown.

After 4 hours of random IP scanning, here's my personal contribution to this analysis:

I found 6144 hosts with an Oracle TNS listener.

On the 6144 ports, 4266 were closed, 1780 were filtered and the 98 remaining were simply open.