CVE-2024-21444: Windows 10 1507 WDAC RCE Vulnerability

CVE-2024-21444 Overview

CVE-2024-21444 is a remote code execution vulnerability in the Microsoft Windows Data Access Components (WDAC) OLE DB provider for SQL Server. The flaw stems from an integer overflow condition tracked as [CWE-190]. An attacker who tricks an authenticated user into connecting to a malicious SQL Server can execute arbitrary code in the context of that user. Microsoft addressed the issue in the March 2024 Patch Tuesday release across all supported Windows client and server editions.

Critical Impact

Successful exploitation grants attackers code execution with the privileges of the targeted user, enabling lateral movement, credential theft, and persistence on Windows endpoints and servers.

Affected Products

• Microsoft Windows 10 (1507, 1607, 1809, 21H2, 22H2)
• Microsoft Windows 11 (21H2, 22H2, 23H2)
• Microsoft Windows Server 2008, 2012, 2016, 2019, 2022, and Server 2022 23H2

Discovery Timeline

• 2024-03-12 - CVE-2024-21444 published to NVD and Microsoft releases security patch
• 2024-12-05 - Last updated in NVD database

Technical Details for CVE-2024-21444

Vulnerability Analysis

The vulnerability resides in the OLE DB provider for SQL Server, a WDAC component used by Windows applications to connect to SQL Server data sources. The provider mishandles arithmetic on attacker-controlled length or size values during response processing. This produces an integer overflow [CWE-190] that leads to incorrect memory allocation and subsequent memory corruption. Exploitation requires network access to a malicious server and user interaction, but no prior authentication or elevated privileges.

Root Cause

The root cause is an integer overflow inside the OLE DB SQL Server provider. When the client parses server responses, size calculations on untrusted fields wrap past the maximum integer boundary. The undersized buffer that follows allows out-of-bounds writes during data copy operations. These writes corrupt adjacent heap structures and create a path for arbitrary code execution.

Attack Vector

An attacker hosts a malicious SQL Server endpoint and coerces a victim into initiating an OLE DB connection. The lure is typically a crafted Office document, link, or application that triggers a SQL client connection string referencing the attacker-controlled host. When the victim connects, the rogue server returns a malformed protocol response that triggers the integer overflow inside the client-side OLE DB provider. Code then executes under the victim's user context on the Windows host.

No verified public proof-of-concept code is available. The vulnerability mechanism is documented in the Microsoft CVE-2024-21444 Advisory.

Detection Methods for CVE-2024-21444

Indicators of Compromise

• Outbound TCP connections from workstations to untrusted external hosts on SQL Server ports (typically 1433) or dynamically negotiated ports.
• Unexpected child processes spawned from applications that load msoledbsql.dll or sqloledb.dll, including Office applications and custom line-of-business tools.
• Crash events or Windows Error Reporting entries referencing the OLE DB SQL provider in faulting module fields.

Detection Strategies

• Hunt for processes loading msoledbsql.dll or sqloledb.dll that subsequently invoke cmd.exe, powershell.exe, or other living-off-the-land binaries.
• Inspect EDR telemetry for memory allocation anomalies and heap corruption signals within processes that establish OLE DB sessions to non-corporate SQL endpoints.
• Correlate user-initiated document opens with new outbound SQL Server connections to flag social-engineering driven exploitation attempts.

Monitoring Recommendations

• Restrict and log egress traffic to TCP 1433 and 1434 at the perimeter, allowing only sanctioned database servers.
• Forward Windows Defender, EDR, and Sysmon image-load events for OLE DB libraries into a centralized data lake for retroactive hunting.
• Track patch compliance for the March 2024 Windows cumulative updates across all endpoint and server inventories.

How to Mitigate CVE-2024-21444

Immediate Actions Required

• Apply the March 2024 Microsoft security updates to every supported Windows 10, Windows 11, and Windows Server build listed in the advisory.
• Block outbound SQL Server traffic from user endpoints to external networks at the firewall.
• Enforce user awareness training and Attack Surface Reduction rules that limit Office applications from launching unexpected network connections.

Patch Information

Microsoft released fixes for CVE-2024-21444 on March 12, 2024 as part of Patch Tuesday. Administrators should consult the Microsoft CVE-2024-21444 Advisory for the specific KB articles that map to each affected Windows version and apply the corresponding cumulative update.

Workarounds

• Where patching is delayed, restrict the OLE DB provider's ability to reach untrusted networks by enforcing host-based firewall rules limiting outbound SQL Server connectivity to approved internal database servers.
• Disable or remove the OLE DB SQL Server provider on systems that do not require SQL connectivity, reducing the exposed attack surface.
• Apply application allowlisting to prevent unsigned or unknown binaries from loading msoledbsql.dll and initiating arbitrary database connections.