CVE-2024-49076 in Windows
Summary
by MITRE • 12/12/2024
Windows Virtualization-Based Security (VBS) Enclave Elevation of Privilege Vulnerability
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Analysis
by VulDB Data Team • 01/08/2025
This vulnerability resides within Windows Virtualization-Based Security (VBS) enclaves, representing a critical elevation of privilege flaw that undermines the fundamental security assurances provided by hardware-based isolation mechanisms. The vulnerability affects the enclave implementation within VBS, which is designed to protect sensitive operations through secure memory regions that are isolated from the main operating system. Enclaves serve as trusted execution environments where cryptographic operations, credential handling, and other security-critical processes execute in isolation from the rest of the system. The flaw allows an authenticated attacker with low-privilege access to potentially escalate their privileges to SYSTEM level, effectively bypassing the isolation guarantees that VBS enclaves are meant to provide.
The technical implementation issue stems from insufficient validation of enclave entry parameters and potential memory corruption vulnerabilities within the VBS subsystem. This vulnerability manifests when the system processes enclave requests or handles memory management operations within the secure environment. The flaw likely involves improper bounds checking, memory layout issues, or insufficient input sanitization during enclave initialization or operation phases. Attackers can exploit this weakness by crafting malicious enclave calls or manipulating the enclave execution environment to achieve privilege escalation. The vulnerability affects Windows 10 and Windows 11 systems that have VBS enabled, particularly those utilizing Windows Defender Application Control or other security features that rely on enclave-based protection mechanisms.
The operational impact of this vulnerability is severe as it directly compromises the core security model of modern Windows systems that depend on hardware-based isolation. Security features such as Credential Guard, Device Guard, and Windows Defender Application Control all rely on VBS enclaves for their effectiveness. An attacker who successfully exploits this vulnerability could gain complete control over the system, access encrypted credentials, extract sensitive data, or establish persistent backdoors. The vulnerability is particularly concerning because it operates within the trusted execution environment where security-sensitive operations are expected to be isolated from regular system processes. This flaw undermines the security assurances provided by Microsoft's hardware security features and could enable attackers to bypass multiple layers of security controls that are designed to protect against sophisticated attacks.
Mitigation strategies should prioritize immediate patch deployment from Microsoft, as this vulnerability requires vendor-provided fixes to address the underlying implementation flaws. Organizations should also consider disabling VBS features temporarily if immediate patching is not feasible, though this reduces overall system security posture. Security monitoring should focus on detecting anomalous enclave activity, unusual privilege escalation attempts, and potential exploitation indicators within system logs. The vulnerability aligns with CWE-121 for heap-based buffer overflow conditions and may relate to ATT&CK technique T1068 for local privilege escalation through kernel exploits. System administrators should implement strict access controls, monitor for unauthorized enclave modifications, and maintain comprehensive audit trails for security-sensitive operations. Additionally, organizations should review their security configurations to ensure that VBS is properly implemented and that only necessary security features are enabled to minimize attack surface while maintaining operational effectiveness.