CVE-2024-38087: Microsoft SQL Server 2016 RCE Vulnerability

CVE-2024-38087 Overview

CVE-2024-38087 is a remote code execution vulnerability affecting the Microsoft SQL Server Native Client Object Linking and Embedding Database (OLE DB) Provider. The flaw is classified as a double free memory corruption issue ([CWE-415]) that attackers can trigger over the network when a user connects to a malicious SQL Server instance. Exploitation requires user interaction, such as initiating a database connection using an affected client component. Successful exploitation allows attackers to execute arbitrary code in the context of the connecting client, leading to full compromise of confidentiality, integrity, and availability.

Critical Impact
Attackers who convince a user to connect to an attacker-controlled SQL Server can execute arbitrary code on the client system, compromising the endpoint fully.

Affected Products

Microsoft SQL Server 2016
Microsoft SQL Server 2017
Microsoft SQL Server 2019
Microsoft SQL Server 2022

Discovery Timeline

2024-07-09 - CVE-2024-38087 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-38087

Vulnerability Analysis

The vulnerability resides in the SQL Server Native Client OLE DB Provider, a client-side data access component used by applications to communicate with SQL Server instances. Microsoft classifies the issue as a remote code execution flaw stemming from a double free condition ([CWE-415]). A double free occurs when the same region of memory is released twice, corrupting heap metadata and enabling attackers to influence subsequent memory allocations.

Exploitation requires that a victim initiate a connection to an attacker-controlled SQL Server endpoint using the vulnerable OLE DB Provider. During the connection handshake or response processing, malformed server responses trigger the double free condition in client memory management. Attackers who control heap layout can convert this corruption into arbitrary code execution within the client process. The attack targets the client, not the server, making phishing and social engineering the primary delivery mechanisms for coercing connections to hostile database endpoints.

Root Cause

The root cause is improper memory management in the OLE DB Provider's handling of server responses, where a memory buffer is released more than once. This creates a window in which heap metadata can be manipulated to hijack control flow.

Attack Vector

The attack vector is network-based with required user interaction. An attacker hosts a malicious SQL Server endpoint and induces a target user to connect using an application that leverages the SQL Server Native Client OLE DB Provider. See the Microsoft Security Update Guide for technical guidance.

No verified public proof-of-concept code is available. The vulnerability mechanism relies on malformed protocol responses triggering the double free in the client-side provider during connection processing.

Detection Methods for CVE-2024-38087

Indicators of Compromise

Outbound TCP connections from workstations to untrusted SQL Server endpoints on port 1433 or custom database ports.
Unexpected child processes spawned by applications hosting msoledbsql.dll or the SQL Server Native Client libraries.
Crash reports or Windows Error Reporting entries referencing OLE DB Provider modules following external database connections.

Detection Strategies

Inspect endpoint telemetry for processes loading the SQL Server Native Client OLE DB Provider that subsequently execute shells, scripting hosts, or LOLBins.
Correlate network flow data with process activity to identify database client connections to non-corporate or newly observed external IP addresses.
Monitor for anomalous memory allocation patterns or exceptions raised within processes using the OLE DB Provider.

Monitoring Recommendations

Alert on any workstation-initiated database connections traversing perimeter firewalls to external destinations.
Track deployed versions of the SQL Server Native Client across the estate and flag unpatched hosts.
Ingest Sysmon Event ID 7 (Image Loaded) telemetry for msoledbsql.dll and related provider libraries into the SIEM for baseline analysis.

How to Mitigate CVE-2024-38087

Immediate Actions Required

Apply the Microsoft security updates referenced in the MSRC advisory for CVE-2024-38087 to all affected SQL Server versions and client installations.
Inventory endpoints and servers running the SQL Server Native Client OLE DB Provider and prioritize patching client-side installations.
Restrict outbound SQL Server protocol traffic (TCP 1433 and custom ports) from user workstations to only sanctioned database hosts.

Patch Information

Microsoft released security updates addressing CVE-2024-38087 for SQL Server 2016, 2017, 2019, and 2022. Refer to the Microsoft Security Update Guide for build numbers and cumulative update packages that remediate the vulnerability.

Workarounds

Block outbound TCP 1433 and other SQL Server ports at the perimeter firewall for endpoints that do not require direct external database access.
Enforce application allowlisting to prevent unauthorized applications from loading the SQL Server Native Client OLE DB Provider.
Educate users about connection prompts and phishing lures that direct them to unfamiliar database servers.

bash

# Configuration example: block outbound SQL Server traffic on Windows endpoints
New-NetFirewallRule -DisplayName "Block Outbound SQL Server 1433" `
  -Direction Outbound `
  -Protocol TCP `
  -RemotePort 1433 `
  -Action Block `
  -Profile Any