CVE-2024-26173 is a high-severity elevation of privilege vulnerability affecting Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The root cause is improper input validation (CWE-20) within the Windows kernel, which allows a local attacker with limited privileges (low privilege) to escalate their rights to higher privilege levels. The vulnerability does not require user interaction and has a low attack complexity, meaning it can be exploited relatively easily by an attacker who already has some access to the system. The CVSS 3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability. Specifically, successful exploitation could allow an attacker to execute arbitrary code in kernel mode, bypass security controls, and potentially take full control of the affected system. Although no known exploits are currently reported in the wild, the vulnerability’s characteristics make it a significant risk, especially in environments where Windows 10 Version 1809 remains in use. The vulnerability is unpatched as no patch links are provided, increasing the urgency for mitigation. The vulnerability scope is limited to Windows 10 Version 1809, which is an older but still widely deployed version in some enterprise environments. The vulnerability’s exploitation vector is local (AV:L), requiring the attacker to have some level of access to the system, but no user interaction is needed (UI:N). The vulnerability’s impact spans confidentiality, integrity, and availability (all rated high), indicating that exploitation could lead to full system compromise.

For European organizations, the impact of CVE-2024-26173 can be substantial, particularly for those still operating legacy Windows 10 Version 1809 systems. Successful exploitation could allow attackers to gain kernel-level privileges, enabling them to bypass security mechanisms, install persistent malware, steal sensitive data, disrupt critical services, or move laterally within networks. This is especially critical for sectors such as finance, healthcare, government, and critical infrastructure, where data confidentiality and system availability are paramount. The elevation of privilege vulnerability could be leveraged as a stepping stone in multi-stage attacks, including ransomware or espionage campaigns. Given the lack of known exploits in the wild, the immediate risk is moderate, but the potential for weaponization is high. Organizations with outdated systems or insufficient patch management processes face increased exposure. The vulnerability also poses a risk to managed service providers and cloud environments that still run affected Windows 10 versions, potentially affecting multiple clients. The impact is compounded by the fact that no user interaction is required, enabling stealthy exploitation by insiders or attackers who have gained limited access through other means.

1. Immediate upgrade or patching: Organizations should prioritize upgrading affected systems from Windows 10 Version 1809 to a supported and patched version of Windows 10 or Windows 11. If upgrading is not immediately feasible, monitor Microsoft’s security advisories closely for patches related to CVE-2024-26173 and apply them promptly once available. 2. Restrict local access: Limit local user accounts and enforce the principle of least privilege to reduce the number of users who can execute code locally. Disable or restrict unnecessary local accounts and services that could be leveraged to exploit this vulnerability. 3. Implement application control and endpoint protection: Deploy advanced endpoint detection and response (EDR) solutions capable of detecting suspicious kernel-level activity or privilege escalation attempts. Use application whitelisting to prevent unauthorized code execution. 4. Network segmentation and monitoring: Segment critical systems to limit lateral movement opportunities if an attacker exploits this vulnerability. Monitor logs and system behavior for signs of privilege escalation or kernel exploitation attempts. 5. Harden system configurations: Disable or restrict legacy protocols and services that may increase attack surface on Windows 10 Version 1809 systems. Enforce strong authentication and access controls. 6. Incident response preparedness: Develop and test incident response plans specifically addressing privilege escalation scenarios to enable rapid containment and remediation. 7. User awareness and training: Educate users about the risks of local privilege escalation vulnerabilities and the importance of reporting suspicious activity promptly. These mitigations go beyond generic patching advice by emphasizing system upgrades, access restrictions, advanced detection, and organizational preparedness.