CVE-2024-49002 Overview
CVE-2024-49002 is a remote code execution vulnerability in the Microsoft SQL Server Native Client. The flaw is classified as a heap-based buffer overflow [CWE-122] and affects SQL Server 2016, 2017, and 2019 on x64 platforms. Exploitation requires user interaction, typically convincing a victim to connect to an attacker-controlled SQL Server instance. A successful attack allows an attacker to execute arbitrary code in the context of the victim process. Microsoft published the advisory on November 12, 2024.
Critical Impact
An attacker who successfully exploits this vulnerability can execute arbitrary code on the victim system, leading to full compromise of confidentiality, integrity, and availability.
Affected Products
- Microsoft SQL Server 2016 (x64)
- Microsoft SQL Server 2017 (x64)
- Microsoft SQL Server 2019 (x64)
Discovery Timeline
- 2024-11-12 - CVE-2024-49002 published to NVD
- 2024-11-12 - Microsoft releases security update via the Microsoft Security Update Guide CVE-2024-49002
- 2024-11-15 - Last updated in NVD database
Technical Details for CVE-2024-49002
Vulnerability Analysis
The vulnerability resides in the SQL Server Native Client (SNAC), the client-side data access component used by applications to communicate with Microsoft SQL Server. The flaw is a heap-based buffer overflow [CWE-122] triggered during the processing of data received from a SQL Server. An attacker controlling a malicious server can return crafted responses that overflow a heap buffer in the client, corrupting adjacent memory structures. With reliable heap layout manipulation, the attacker can redirect execution flow and achieve arbitrary code execution under the privileges of the connecting application. Because the vulnerable code path is reached over the standard SQL Server wire protocol, the attack surface extends to any host running an application built against the affected SNAC versions.
Root Cause
The root cause is improper validation of length or size fields in attacker-supplied response data before copying it into a fixed-size heap allocation. Insufficient bounds checking allows the write to extend beyond the allocated buffer.
Attack Vector
Exploitation requires a user to initiate a connection from a vulnerable client to an attacker-controlled SQL Server instance. The attacker can deliver this via a phishing lure, a malicious connection string in a document, or a compromised internal server. No prior authentication on the client is required.
No public proof-of-concept exploit is available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Detailed exploitation primitives are described in prose only; refer to the Microsoft Security Update Guide CVE-2024-49002 for vendor information.
Detection Methods for CVE-2024-49002
Indicators of Compromise
- Outbound TCP connections from workstations or application servers to untrusted external hosts on port 1433 or other custom SQL Server listener ports.
- Unexpected child processes spawned by applications that link against sqlncli11.dll or related SQL Server Native Client libraries.
- Crash dumps or Windows Error Reporting entries referencing heap corruption inside the SQL Server Native Client module.
Detection Strategies
- Monitor process telemetry for anomalous code execution originating from processes that load the SQL Server Native Client DLL.
- Inspect network flows for SQL Server connections crossing trust boundaries, especially from end-user endpoints to internet-facing IP addresses.
- Correlate application crashes with subsequent suspicious process creation events within a short time window.
Monitoring Recommendations
- Enable detailed process and module-load logging on systems that run applications using SNAC for database connectivity.
- Alert on DNS resolutions and TCP sessions to SQL Server endpoints outside the approved database server inventory.
- Maintain an inventory of applications that depend on the SQL Server Native Client and prioritize them for patch verification.
How to Mitigate CVE-2024-49002
Immediate Actions Required
- Apply the November 2024 Microsoft security updates for SQL Server 2016, 2017, and 2019 as documented in the Microsoft Security Update Guide CVE-2024-49002.
- Identify all endpoints and servers with the SQL Server Native Client installed, including legacy applications that bundle SNAC redistributables.
- Restrict outbound TCP 1433 and other SQL Server ports from user workstations to only sanctioned database hosts.
Patch Information
Microsoft has released cumulative updates addressing CVE-2024-49002 for SQL Server 2016, 2017, and 2019. Administrators should consult the Microsoft Security Update Guide CVE-2024-49002 for the specific build numbers and deploy them through standard patch management workflows. Verify the version of sqlncli*.dll on each system after patching to confirm remediation.
Workarounds
- Block outbound connections to untrusted SQL Server endpoints at the perimeter firewall and host-based firewall.
- Migrate applications from the deprecated SQL Server Native Client to the supported Microsoft OLE DB Driver for SQL Server (MSOLEDBSQL) or the ODBC Driver for SQL Server.
- Enforce application allowlisting to prevent execution of unauthorized binaries spawned from database client processes.
# Verify installed SQL Server Native Client version on Windows hosts
Get-WmiObject -Class Win32_Product | Where-Object { $_.Name -like "*SQL Server*Native Client*" } | Select-Object Name, Version
# Block outbound SQL Server traffic to non-approved hosts (example)
New-NetFirewallRule -DisplayName "Block Outbound SQL 1433" -Direction Outbound -Protocol TCP -RemotePort 1433 -Action Block
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
