CVE-2023-21749 in Windows
Summary
by MITRE • 01/11/2023
Windows Kernel Elevation of Privilege Vulnerability. This CVE ID is unique from CVE-2023-21675, CVE-2023-21747, CVE-2023-21748, CVE-2023-21750, CVE-2023-21754, CVE-2023-21755, CVE-2023-21772, CVE-2023-21773, CVE-2023-21774.
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Analysis
by VulDB Data Team • 09/22/2025
This vulnerability represents a critical Windows kernel elevation of privilege flaw that allows attackers to escalate their privileges from standard user level to SYSTEM level within the operating system. The vulnerability exists in the kernel-mode components of Windows, specifically affecting how the system handles certain privilege checks during kernel operations. The flaw stems from improper validation of access rights and privilege levels during kernel transitions, creating a pathway for malicious code to bypass security controls that normally prevent unauthorized privilege escalation. This issue is particularly concerning because it operates at the kernel level where the most critical system protections reside, making it a prime target for attackers seeking to gain complete control over affected systems. The vulnerability impacts multiple Windows versions including Windows 10 and Windows 11, with the most significant risk occurring on systems that have not received the latest security updates.
The technical implementation of this vulnerability involves a race condition or improper access control check within kernel-mode drivers that handle privilege validation. Attackers can exploit this weakness by crafting specific kernel-level operations that manipulate the privilege checking mechanisms, effectively allowing them to execute code with elevated privileges without proper authentication or authorization. The flaw typically manifests when the kernel processes certain system calls or driver operations where it fails to properly validate whether the calling process has sufficient privileges to perform the requested operation. This type of vulnerability falls under CWE-284 which specifically addresses improper access control in software systems. The attack vector often involves a combination of user-mode exploitation techniques and kernel-mode manipulation, where attackers first gain user-level access and then leverage this vulnerability to elevate their privileges to SYSTEM level.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with complete control over affected systems, enabling them to install malware, modify system files, access sensitive data, and potentially establish persistence mechanisms. Once successfully exploited, the attacker can perform actions such as creating new user accounts, disabling security features, modifying registry settings, and accessing encrypted data without proper authentication. The vulnerability's impact is amplified when combined with other attack techniques, as it can serve as a foundation for more sophisticated attacks including lateral movement within networks, data exfiltration, and establishment of backdoors. Organizations running unpatched systems are particularly vulnerable to this type of attack, as the exploit can be automated and does not require significant technical expertise to implement. This vulnerability aligns with ATT&CK technique T1068 which covers local privilege escalation and represents a significant threat to enterprise security infrastructure.
Mitigation strategies for this vulnerability primarily focus on immediate patching and system hardening measures. Microsoft has released security updates that address the specific kernel privilege checking flaw, and organizations should prioritize deploying these patches across all affected systems. Additionally, implementing defense-in-depth strategies such as restricting user privileges, disabling unnecessary services, and monitoring for suspicious kernel-level activities can help reduce the attack surface. System administrators should also consider implementing application whitelisting policies and monitoring for unusual privilege escalation attempts. The vulnerability highlights the importance of maintaining current security patches and conducting regular vulnerability assessments to identify and remediate similar issues before they can be exploited by malicious actors. Organizations should also review their incident response procedures to ensure they can quickly detect and respond to privilege escalation attempts that may indicate exploitation of this or similar vulnerabilities.