CVE-2022-35771 is a high-severity elevation of privilege vulnerability affecting Microsoft Windows 10 Version 1809, specifically impacting the Windows Defender Credential Guard component. Credential Guard is a security feature designed to isolate and protect derived domain credentials, such as NTLM hashes and Kerberos tickets, by running them in a secure, isolated environment using virtualization-based security. This vulnerability, classified under CWE-269 (Improper Privilege Management), allows an attacker with limited privileges (low-level privileges) on a vulnerable system to escalate their privileges to higher levels, potentially SYSTEM or administrative privileges, without requiring user interaction. The CVSS v3.1 base score of 7.8 reflects the significant impact on confidentiality, integrity, and availability, with an attack vector requiring local access (AV:L), low complexity (AC:L), and low privileges (PR:L). The vulnerability does not require user interaction (UI:N) and affects the same security scope (S:U). Exploiting this flaw could allow an attacker to bypass Credential Guard protections, gaining access to sensitive credential material and potentially compromising the entire system or network. Although no known exploits are currently reported in the wild, the vulnerability's nature and impact make it a critical concern for organizations still running Windows 10 Version 1809, which is an older release with extended support. The lack of publicly available patches at the time of reporting increases the urgency for mitigation and monitoring.

For European organizations, this vulnerability poses a significant risk, especially for those operating legacy systems or environments where Windows 10 Version 1809 remains in use. Successful exploitation could lead to unauthorized privilege escalation, enabling attackers to access sensitive credentials protected by Credential Guard, potentially leading to lateral movement within corporate networks, data exfiltration, or disruption of critical services. Sectors such as finance, healthcare, government, and critical infrastructure, which often have stringent security requirements and handle sensitive data, could face severe consequences including regulatory penalties under GDPR if breaches occur. The vulnerability undermines a key security control designed to protect credentials, increasing the risk of persistent threats and advanced attacks. Additionally, the local attack vector implies that insider threats or attackers who have gained initial footholds through other means could leverage this vulnerability to deepen their access and control.

European organizations should prioritize upgrading or patching affected systems to versions of Windows 10 beyond 1809 where this vulnerability is resolved. In the absence of official patches, organizations should implement strict access controls to limit local user privileges and restrict the ability to execute untrusted code. Employing application whitelisting and endpoint detection and response (EDR) solutions can help detect and prevent exploitation attempts. Network segmentation should be enforced to limit lateral movement if an attacker gains local access. Regular auditing of privileged accounts and monitoring for unusual privilege escalation activities are critical. Additionally, organizations should consider disabling or restricting Credential Guard only if absolutely necessary and with full understanding of the security trade-offs. Maintaining up-to-date asset inventories to identify systems running vulnerable versions is essential for targeted remediation. Finally, user training to reduce the risk of initial compromise and maintaining robust incident response plans will help mitigate the broader impact.