Filter Contents

The section Filter Contents belongs to Linux Fundamentals module.

sudo openvpn academy-regular.ovpn # Make sure you have openvpn installed.

How many services are listening on the target system on all interfaces? (Not on localhost and IPv4 only)

Open a terminal and use netstat to find the listening services on all interfaces:

netstat -tln | grep -v tcp6 | grep -v "127.0.0." | grep LISTEN | wc -l

• -t → Show TCP connections only.
• -l → Show only listening ports (servers waiting for connections).
• -n → Show numeric IP addresses and port numbers (don't resolve names).

Determine what user the ProFTPd server is running under. Submit the username as the answer.

To check the username, use the ps command:

ps aux | grep proftpd

The first word of the output is the username.

Use cURL from your Pwnbox (not the target machine) to obtain the source code of the "https://www.inlanefreight.com" website and filter all unique paths ("https://www.inlanefreight.com/directory" or "/another/directory") of that domain. Submit the number of these paths as the answer.

Use the curl command to get the code then filter it via tr and grep:

curl https://www.inlanefreight.com | tr " " "\n" | grep -Eo "https://www.inlanefreight.com[^\"']*" | sort -u | wc -l

• curl https://www.inlanefreight.com: Fetches the raw HTML source code of the website.
• tr " " "\n": Splits strings by replacing spaces with newlines to ensure each URL/path sits on its own line.
• grep -Eo "https://www.inlanefreight.com[^\"']*": Isolates only strings that start with the target domain, extracting everything up to a closing quote.
• sort -u: Alphabetically sorts the lines and removes duplicates to retain only unique paths.
• wc -l: Counts the final number of total lines outputted.

The -E flag for grep used to tell that it is going to use Enhanced RegEx.