Hi,
does anybody know how HTB blocks nmap port scan? I tried to nmap scan 88.198.233.174 today and they all seem down.
root@osboxes:~# nmap -p37496 88.198.233.174
Starting Nmap 7.70 ( https://nmap.org ) at 2018-08-20 11:23 EDT
Note: Host seems down. If it is really up, but blocking our ping probes, try -Pn
Nmap done: 1 IP address (0 hosts up) scanned in 3.18 seconds
root@osboxes:~# nmap -p 37496 88.198.233.174
Starting Nmap 7.70 ( https://nmap.org ) at 2018-08-20 11:29 EDT
Note: Host seems down. If it is really up, but blocking our ping probes, try -Pn
Nmap done: 1 IP address (0 hosts up) scanned in 3.17 seconds
root@osboxes:~# nmap -sT -p37496 88.198.233.174
Starting Nmap 7.70 ( https://nmap.org ) at 2018-08-20 11:30 EDT
Note: Host seems down. If it is really up, but blocking our ping probes, try -Pn
Nmap done: 1 IP address (0 hosts up) scanned in 3.11 seconds
root@osboxes:~# nmap -sS -p37496 88.198.233.174
Starting Nmap 7.70 ( https://nmap.org ) at 2018-08-20 11:30 EDT
Note: Host seems down. If it is really up, but blocking our ping probes, try -Pn
Nmap done: 1 IP address (0 hosts up) scanned in 3.12 seconds
root@osboxes:~# nmap -sA -p37496 88.198.233.174
Starting Nmap 7.70 ( https://nmap.org ) at 2018-08-20 11:30 EDT
Note: Host seems down. If it is really up, but blocking our ping probes, try -Pn
Nmap done: 1 IP address (0 hosts up) scanned in 3.13 seconds
eventhough curl gives result:
root@osboxes:~# curl 88.198.233.174:37496
<html>
<head>
<title>Login - Lernaean</title>
</head>
<body style="background-color: #cd4e7b;">
<center>
<br><br><br>
<h1><u>Administrator Login</u></h1>
<h2>--- CONFIDENTIAL ---</h2>
<h2>Please do not try to guess my password!</h2>
<form method="POST">
<input type="password" name="password"><br><br>
<input type="submit" value="Submit">
</form>
</center>
</body>
How can a webserver allow 3 Way Handshake from HTML Request but drop a SYN Package of a nmap scan?