Enumeration
Machine IP → 192.168.80.107
Network Scan
Nmap scan → nmap -A -Pn -p- -T4 -o nmap.txt 192.168.80.107
OS Detection → OSs: Unix, Linux; CPE: cpe:/o:linux:linux_kernel
| Port | Service | Other details (if any) |
|---|---|---|
| 21 | FTP | ProFTPD 1.3.5e |
| 22 | SSH | OpenSSH 7.6p1 Ubuntu 4ubuntu0.3 (Ubuntu Linux; protocol 2.0) |
| 80 | HTTP | Apache httpd 2.4.29 ((Ubuntu)) |
Web Scan
GoBuster scan → gobuster dir -u http://192.168.80.107 -w /home/tanq/installations/SecLists/Discovery/Web-Content/directory-list-lowercase-2.3-medium.txt -x html,php,txt
Directories/files listed →
- index.html
- robots.txt
Robots txt file contains entry of /logs/. However, this is not reachable.
Exploitation
The ftp actually allows anonymous login despite the nmap service scan not listing it. Looking at the contents, there are a bunch of zip files with different user names. Cracking these files with fcrackzip against the rockyou.txt list of passwords, the following zip files were successfully cracked →
- cathrine.zip -
catwoman - homer.zip -
catwoman - tom.zip -
iubire
Unzipping all these with the respective passwords give an id_rsa file for ssh login. All the files are the same, therefore there is only 1 user. Therefore, trying all usernames, the one that works and grants a shell is the user tom.
This gives the user flag. Navigation and other actions seem limited, therefore, checked shell and this revealed shell as /bin/rbash. This is a restricted shell. Used python to spawn a bash instance to escape this.
Privilege Escalation
Looking at the user directory, there is a mysql history file. The key entry here is that of → insert\040into\040support\040(tom,\040xx11yy22!);. This indicates additions of the user tom into the table support.
Checking to see if this is the password for the user tom by using sudo -l, it indeed works out and shows that tom can perform all operations under sudo without a password. Therefore, using sudo su to get root shell, the root flag can be retrieved.