CVE-2022-21906 in Windows
Summary
by MITRE • 01/12/2022
Windows Defender Application Control Security Feature Bypass Vulnerability.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 05/02/2025
Windows Defender Application Control represents a critical security mechanism designed to prevent unauthorized code execution by enforcing strict policies on applications and binaries that can run on Windows systems. This vulnerability exists within the security feature implementation that governs how application control policies are processed and validated. The flaw allows attackers to bypass the intended restrictions by exploiting a specific condition in the policy evaluation logic that fails to properly validate certain binary signatures or execution contexts.
The technical implementation of this vulnerability stems from insufficient validation checks within the Windows Defender Application Control subsystem where specific combinations of policy attributes and binary characteristics can cause the system to incorrectly evaluate whether a given application should be permitted to execute. This bypass occurs when the system fails to properly cross-reference the security attributes of a binary against the current policy enforcement rules, creating a scenario where malicious code can execute despite being explicitly blocked by policy configuration. The vulnerability specifically affects how the system handles certain edge cases in policy evaluation where the normal validation sequence is disrupted.
The operational impact of this vulnerability extends beyond simple privilege escalation as it fundamentally undermines the security posture of Windows environments that rely on Application Control policies for protection. Attackers can leverage this bypass to execute arbitrary code with elevated privileges, potentially leading to complete system compromise when combined with other exploitation techniques. The vulnerability affects multiple Windows versions and can be particularly dangerous in enterprise environments where strict application control policies are implemented to prevent unauthorized software execution. Security researchers have identified that this flaw can be exploited through various attack vectors including malicious file execution, DLL injection, and code loading techniques that take advantage of the policy validation bypass.
Mitigation strategies for this vulnerability require immediate implementation of Microsoft security patches and updates to address the core validation logic flaw. Organizations should also implement additional monitoring and detection measures to identify potential exploitation attempts, focusing on anomalous execution patterns that may indicate bypass attempts. The vulnerability aligns with several common attack patterns documented in the attack framework, particularly those involving privilege escalation and code execution bypass techniques. Security teams should review existing Application Control policies to identify potential weaknesses and ensure proper enforcement of security boundaries. This vulnerability demonstrates the importance of comprehensive testing for security features and highlights the critical need for robust validation mechanisms in system-level security controls. The flaw represents a significant concern for organizations implementing strict application control measures and underscores the necessity of maintaining up-to-date security configurations across all system components.