CVE-2018-0902 in Windows
Summary
by MITRE
The Cryptography Next Generation (CNG) kernel-mode driver (cng.sys) in Windows 10 Gold, 1511, 1607, 1703, and 1709. Windows Server 2016 and Windows Server, version 1709 allows a security feature bypass vulnerability due to the way the kernel-mode driver validates and enforces impersonation levels, aka "Windows Security Feature Bypass Vulnerability". This CVE is unique from CVE-2018-0884.
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Analysis
by VulDB Data Team • 08/17/2024
The vulnerability described in CVE-2018-0902 resides within the Cryptography Next Generation kernel-mode driver component of Microsoft Windows operating systems, specifically affecting versions including Windows 10 Gold through 1709 and Windows Server 2016 through version 1709. This represents a critical security feature bypass flaw that fundamentally undermines the operating system's ability to properly enforce security policies at the kernel level. The issue manifests through improper validation and enforcement of impersonation levels within the cng.sys driver, which is responsible for handling cryptographic operations and security token management within the Windows kernel space.
The technical flaw stems from the kernel-mode driver's inadequate handling of security impersonation levels during cryptographic operations, allowing malicious actors to bypass intended security controls that should prevent unauthorized access to cryptographic services. This vulnerability specifically affects how the CNG driver validates security contexts when processing requests from user-mode applications, creating a pathway for attackers to escalate privileges or access restricted cryptographic resources without proper authorization. The flaw operates at the kernel level, making it particularly dangerous as it can be exploited to circumvent Windows' security model that relies on proper impersonation level enforcement for cryptographic operations.
The operational impact of this vulnerability is severe as it enables attackers to bypass Windows security features that are fundamental to maintaining system integrity and protecting sensitive cryptographic operations. An attacker who successfully exploits this vulnerability could potentially perform unauthorized cryptographic operations, access protected keys or certificates, and gain elevated privileges within the system. This security bypass affects the core cryptographic infrastructure of Windows, potentially allowing for credential theft, encryption key compromise, and unauthorized access to protected system resources. The vulnerability is particularly concerning because it operates at the kernel level where the most critical security controls are enforced, making it a prime target for advanced persistent threats and privilege escalation attacks.
Mitigation strategies for this vulnerability require immediate patching of affected Windows versions through Microsoft's security updates, as the primary fix involves correcting the impersonation level validation logic within the CNG kernel driver. Organizations should implement network segmentation and access controls to limit exposure while patches are deployed, and monitor for suspicious cryptographic activity or privilege escalation attempts. The vulnerability aligns with CWE-284 (Improper Access Control) and follows patterns commonly seen in kernel-mode exploitation techniques that leverage security feature bypasses to gain unauthorized system access. This issue is distinct from CVE-2018-0884 and represents a separate but equally critical vulnerability in Windows security architecture that requires immediate attention from system administrators and security teams to prevent potential exploitation by malicious actors.