Exploiting Windows SMB v3.1.1 | CVE-2020-0796 | SMBGhost | CORONABLUE

Description

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.

CVE ID

CVE-2020-0796

Why it is wormable?

Remember MS17-010??? ok.. Remember wannaCry!!!!!! yes… that is it. Whenever there is any vulnerability that might be used by any malicious hacker group to spread any kind of malware/computer virus/worm, then the vulnerability can be called as “Wormable“.

Targets

• Windows 10 Version 1903 for 32-bit Systems
• Windows 10 Version 1903 for ARM64-based Systems
• Windows 10 Version 1903 for x64-based Systems
• Windows 10 Version 1909 for 32-bit Systems
• Windows 10 Version 1909 for ARM64-based Systems
• Windows 10 Version 1909 for x64-based Systems
• Windows Server, version 1903 (Server Core installation)
• Windows Server, version 1909 (Server Core installation)

Agenda

• Vulnerability Detection via Python Script
• Vulnerability Detection via unofficial Nmap script
• Exploitation using python script that will cause DoS
• Workaround

Disclaimer: This video is ONLY for educational & research purpose. Any misuse of the content of this video is strictly prohibited. BugTestLab or me will not be accountable for any illegal activities.

Our Target

Tools Required

• Python 3.0+
• Nmap

How to detect

• Python Script

• Unofficial Nmap Script

Exploitation

Currently there is no public exploit available for Remote Code Execution (RCE) but there are couple of scripts available which can cause Denial of Services (DoS) to the target system.

Exploit Code

Below is the screenshot which is showing DoS process using existing exploit code:

Research Areas

• Local Privilege Escalation 
  • Exploit code in C
  • Metasploit Module

• Remote Code Execution : TO DO
• MSF Module for RCE/PrivEsc

Workarounds

ADV200005 | Microsoft Guidance for Disabling SMBv3 Compression

Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters" DisableCompression -Type DWORD -Value 1 -Force

References