CVE-2023-21755 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-2023-21749, CVE-2023-21750, CVE-2023-21754, CVE-2023-21772, CVE-2023-21773, CVE-2023-21774.
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Analysis
by VulDB Data Team • 09/23/2025
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 resides in the kernel-mode components of Windows, specifically affecting how the system handles certain privilege checks during kernel operations. The flaw enables malicious actors to bypass security mechanisms that normally prevent unauthorized access to privileged system resources and functions. Such vulnerabilities are particularly dangerous because they operate at the core of the operating system where the most sensitive operations occur, making them prime targets for exploitation in advanced persistent threat campaigns.
The technical nature of this vulnerability stems from improper validation of privilege levels within kernel-mode drivers and system components. Attackers can exploit this weakness by crafting specific malicious code or payloads that leverage the kernel's privilege handling mechanisms to gain unauthorized administrative access. This type of vulnerability typically involves race conditions, improper access control checks, or flawed privilege validation logic within the Windows kernel. The vulnerability's classification aligns with CWE-276, which addresses improper privilege management, and may also relate to CWE-787, concerning out-of-bounds writes that could lead to privilege escalation. The exploitability of such flaws often requires a combination of local execution capabilities and specific system configurations that make the vulnerability accessible to attackers.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as it provides attackers with complete control over affected systems. Once exploited, adversaries can manipulate system files, install malware, establish persistence mechanisms, and access all user data without detection. The vulnerability affects multiple Windows versions and could potentially be leveraged in targeted attacks against enterprise networks, government agencies, or critical infrastructure. The risk is particularly elevated when combined with other vulnerabilities in the same vulnerability family, as attackers can chain multiple exploits to achieve more comprehensive system compromise. This vulnerability's impact is further amplified by its potential for automated exploitation, as it may be incorporated into automated attack frameworks that scan for vulnerable systems and deploy exploits without human intervention.
Mitigation strategies for this vulnerability must encompass both immediate patching and operational security measures. Microsoft has released security updates that address the specific kernel privilege validation flaws, and organizations should prioritize applying these patches to all affected systems. Additionally, implementing defense-in-depth strategies including privilege separation, user access controls, and monitoring for suspicious kernel activity can help detect exploitation attempts. Network segmentation and access control policies should be enforced to limit the potential damage from successful exploitation. The vulnerability's characteristics align with ATT&CK technique T1068, which covers local privilege escalation, and T1547, covering registry run keys and startup folder modifications that attackers often use to establish persistence after privilege escalation. Organizations should also consider implementing endpoint detection and response solutions that can identify anomalous kernel behavior indicative of exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify systems that may be vulnerable to similar privilege escalation flaws within the broader Windows kernel ecosystem.