CVE-2023-21823: Windows Graphics Component RCE Vulnerability

CVE-2023-21823 Overview

CVE-2023-21823 is a remote code execution vulnerability in the Windows Graphics Component that allows an attacker to execute arbitrary code on vulnerable systems. This vulnerability exists due to an integer overflow weakness (CWE-190) in the graphics rendering subsystem, which can be exploited to achieve code execution with elevated privileges.

This vulnerability has been added to CISA's Known Exploited Vulnerabilities (KEV) catalog, indicating active exploitation in the wild. Organizations running affected Windows systems should prioritize patching immediately.

Critical Impact

Attackers exploiting this vulnerability can achieve remote code execution on affected Windows systems through the graphics component, potentially leading to complete system compromise. Active exploitation has been observed in the wild.

Affected Products

• Microsoft Windows 10 (versions 1507, 1607, 1809, 20H2, 21H2, 22H2)
• Microsoft Windows 11 (versions 21H2, 22H2)
• Microsoft Windows Server 2008 (SP2, R2 SP1)
• Microsoft Windows Server 2012 and 2012 R2
• Microsoft Windows Server 2016
• Microsoft Windows Server 2019
• Microsoft Windows Server 2022

Discovery Timeline

• February 14, 2023 - CVE-2023-21823 published to NVD
• October 30, 2025 - Last updated in NVD database

Technical Details for CVE-2023-21823

Vulnerability Analysis

The Windows Graphics Component Remote Code Execution vulnerability stems from an integer overflow condition (CWE-190) within the graphics rendering subsystem. When specially crafted graphical content is processed, the integer overflow can corrupt memory structures, allowing an attacker to redirect execution flow and achieve code execution.

The vulnerability requires local access to the target system but does not require user interaction to exploit. An attacker with low privileges can leverage this vulnerability to elevate privileges and execute arbitrary code in the context of the affected application or system process.

The graphics component is a core Windows subsystem responsible for rendering visual elements across the operating system. Due to its privileged position and deep integration with the kernel, successful exploitation can result in complete system compromise, including the ability to install programs, view, change, or delete data, and create new accounts with full user rights.

Root Cause

The root cause of CVE-2023-21823 is an integer overflow vulnerability (CWE-190) in the Windows Graphics Component. Integer overflow occurs when an arithmetic operation produces a numeric value that exceeds the maximum value that can be represented within the available storage. In this case, the overflow condition can be triggered through specially crafted graphics operations, leading to incorrect memory allocation calculations and subsequent memory corruption.

Attack Vector

The attack vector is local, meaning an attacker must have some level of access to the target system to exploit this vulnerability. Attack scenarios include:

1. Malicious Document Delivery: An attacker could craft a document containing embedded graphics that trigger the vulnerability when rendered
2. Web-based Attack: A user could be enticed to visit a malicious website that delivers content designed to exploit the graphics component
3. Local Privilege Escalation: An attacker with limited access could use this vulnerability to escalate privileges to SYSTEM level

The vulnerability does not require high privileges to exploit, making it accessible to attackers who have gained initial foothold through other means such as phishing or social engineering.

Detection Methods for CVE-2023-21823

Indicators of Compromise

• Unexpected crashes or memory errors in Windows graphics processes such as dwm.exe (Desktop Window Manager)
• Unusual process spawning from graphics-related system processes
• Evidence of integer overflow errors in Windows Event Logs related to GDI or DirectX components
• Suspicious file access patterns to graphics rendering libraries

Detection Strategies

• Monitor for anomalous behavior in the Desktop Window Manager (dwm.exe) and related graphics processes
• Deploy endpoint detection rules to identify exploitation attempts targeting the Windows Graphics Component
• Implement behavioral analysis to detect privilege escalation attempts following graphics component interaction
• Enable Windows Defender Exploit Guard Attack Surface Reduction rules

Monitoring Recommendations

• Enable detailed Windows Security event logging, particularly for process creation events (Event ID 4688)
• Monitor for unusual GDI object creation patterns that may indicate exploitation attempts
• Deploy SIEM rules to correlate graphics process crashes with subsequent suspicious activity
• Utilize SentinelOne's behavioral AI engine to detect and block exploitation attempts in real-time

How to Mitigate CVE-2023-21823

Immediate Actions Required

• Apply Microsoft's February 2023 security updates immediately to all affected systems
• Prioritize patching systems that are exposed to untrusted content or users with low-privilege access
• Enable Windows Defender Exploit Guard memory protection features
• Implement network segmentation to limit lateral movement if exploitation occurs
• Review CISA KEV guidance for additional remediation requirements

Patch Information

Microsoft has released security updates to address this vulnerability as part of the February 2023 Patch Tuesday release. The patches are available through Windows Update, Microsoft Update Catalog, and WSUS. Organizations should refer to the Microsoft Security Response Center advisory for detailed patch information and download links for specific operating system versions.

For systems that cannot be immediately patched, Microsoft Store updates are also required for certain affected components. Administrators should ensure both Windows Update and Microsoft Store updates are applied.

Workarounds

• Restrict execution of untrusted content that could trigger graphics rendering exploitation
• Implement application whitelisting to prevent unauthorized code execution
• Deploy network-level filtering to block delivery of malicious graphics content
• Consider temporarily disabling hardware graphics acceleration on high-risk systems until patches can be applied
• Implement least-privilege access controls to limit the impact of successful exploitation

# Verify patch installation status
wmic qfe list full | findstr /i "KB5022834 KB5022836 KB5022838"

# Enable exploit protection via PowerShell
Set-ProcessMitigation -System -Enable DEP,SEHOP,CFG

# Review Windows Defender Exploit Guard configuration
Get-ProcessMitigation -System