CVE-2020-0675 in Windows
Summary
by MITRE
An information disclosure vulnerability exists in the Cryptography Next Generation (CNG) service when it fails to properly handle objects in memory.To exploit this vulnerability, an attacker would have to log on to an affected system and run a specially crafted application.The security update addresses the vulnerability by correcting how the service handles objects in memory., aka 'Windows Key Isolation Service Information Disclosure Vulnerability'. This CVE ID is unique from CVE-2020-0676, CVE-2020-0677, CVE-2020-0748, CVE-2020-0755, CVE-2020-0756.
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Analysis
by VulDB Data Team • 03/29/2024
The vulnerability described in CVE-2020-0675 represents a critical information disclosure flaw within Microsoft's Cryptography Next Generation (CNG) service, specifically affecting the Windows Key Isolation Service component. This vulnerability stems from improper memory handling practices within the cryptographic service that governs how encryption keys and sensitive cryptographic objects are managed in system memory. The flaw manifests when the CNG service fails to adequately protect memory objects containing cryptographic keys or sensitive data, potentially exposing them to unauthorized access or extraction by malicious processes running on the compromised system.
The technical exploitation of this vulnerability requires an attacker to possess valid user credentials and execute a specially crafted application on the target system. This attack vector aligns with the ATT&CK framework's privilege escalation and credential access techniques, specifically mapping to T1550.001 for legitimate credentials and T1068 for local privilege escalation. The vulnerability's classification under CWE-200 indicates improper information exposure, where sensitive data that should remain protected in memory becomes accessible through flawed memory management routines within the CNG service. The Windows Key Isolation Service, designed to protect cryptographic keys from unauthorized access, fails to maintain proper isolation boundaries when handling memory objects, creating a potential pathway for key extraction.
The operational impact of this vulnerability extends beyond simple information disclosure, as compromised cryptographic keys can undermine the entire security posture of a Windows system. Attackers who successfully exploit this vulnerability could potentially access encrypted data, impersonate legitimate users, or decrypt sensitive communications that were previously protected by the cryptographic service. The memory handling flaw creates a persistent threat surface where even after initial access, attackers can maintain access to cryptographic keys that should remain isolated from user-space applications. This vulnerability particularly affects systems where the CNG service is actively managing encryption keys, including those running Windows 10, Windows Server 2016, and Windows Server 2019, where the service is integral to system security operations.
Microsoft's security update for CVE-2020-0675 addresses the root cause by implementing proper memory handling procedures within the CNG service. The fix ensures that cryptographic objects are correctly isolated in memory and that access controls are properly enforced when handling sensitive data. Organizations should prioritize patch deployment as this vulnerability represents a significant risk to cryptographic security, particularly in environments where sensitive data encryption is critical. The update aligns with industry best practices for memory protection and follows the principle of least privilege by ensuring that cryptographic keys remain isolated from potentially malicious processes. Security teams should monitor for exploitation attempts and consider implementing additional monitoring for unusual memory access patterns that might indicate exploitation of similar vulnerabilities in the cryptographic subsystem.