Windows VBS Vulnerability CVE-2025-47159: A Gateway to Privilege Escalation

Introduction

Windows Virtualization-Based Security (VBS) is a cornerstone of Microsoft's security architecture, designed to isolate critical system processes and protect sensitive data. However, a newly disclosed vulnerability, CVE-2025-47159, threatens this protective barrier by allowing attackers to escalate privileges locally, potentially compromising entire systems.

Technical Information

CVE-2025-47159 arises from a protection mechanism failure within Windows VBS. The flaw specifically involves improper memory boundary checks, which attackers can exploit to bypass hypervisor-enforced isolation. By crafting specific system calls, attackers can inject malicious code into enclave-protected memory, effectively escalating privileges from a low-level user to kernel-level access.

The exploitation process typically involves:

Compromising a low-privilege process through initial access vectors such as phishing.
Leveraging the compromised process to execute crafted system calls (CreateEnclave or CallEnclave).
Injecting malicious code into the VBS enclave memory, exploiting race conditions during enclave initialization.

This vulnerability is particularly concerning due to its ability to evade traditional endpoint detection methods, as malicious payloads can reside within the isolated VBS enclaves.

Patch Information

In the July 2025 Patch Tuesday release, Microsoft addressed a publicly disclosed information disclosure vulnerability in Microsoft SQL Server, identified as CVE-2025-49719. This flaw could potentially allow a remote, unauthenticated attacker to access data from uninitialized memory, leading to unintended information disclosure.

To mitigate this vulnerability, Microsoft has released security updates that modify how SQL Server handles memory operations. The patch ensures that memory is properly initialized before use, preventing unauthorized access to residual data. This update is crucial for maintaining the confidentiality and integrity of data processed by SQL Server.

Administrators are strongly advised to apply the latest security updates to their SQL Server instances promptly. Keeping systems updated is essential to protect against potential exploits targeting this and other vulnerabilities.

Affected Systems and Versions

Windows 11 version 24H2 and later
Windows Server 2025
Systems with Hyper-V enabled

Vendor Security History

Microsoft has previously encountered similar vulnerabilities within its VBS component, notably CVE-2025-21370, highlighting ongoing challenges in securing virtualization technologies. Despite these issues, Microsoft maintains a relatively rapid patch response time, typically addressing critical vulnerabilities within 14 to 30 days.

References

Organizations are urged to promptly apply the provided patches and implement recommended mitigation strategies to safeguard their environments against potential exploitation of CVE-2025-47159.

Source: This report was created using AI

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