CVE-2024-26229 is a heap-based buffer overflow vulnerability identified in the Microsoft Windows 10 Version 1809 operating system, specifically affecting the CSC (Client-Side Caching) service. The vulnerability is categorized under CWE-122, which refers to improper memory handling leading to buffer overflows on the heap. This flaw allows an attacker with limited privileges (local access with low privileges) to execute a carefully crafted operation that causes the CSC service to improperly handle heap memory, resulting in a buffer overflow. The overflow can corrupt memory, potentially allowing the attacker to escalate privileges on the affected system. The vulnerability does not require user interaction and can be exploited locally with low complexity, as indicated by the CVSS vector (AV:L/AC:L/PR:L/UI:N). The impact is severe, affecting confidentiality, integrity, and availability (C:H/I:H/A:H), meaning an attacker could gain elevated privileges, execute arbitrary code, and cause system instability or crashes. The scope is unchanged (S:U), meaning the exploit affects only the vulnerable component without extending to other system components. Although no known exploits are currently reported in the wild, the high CVSS score of 7.8 and the nature of the vulnerability make it a significant risk for systems still running Windows 10 Version 1809, which is an older but still in-use version of Windows 10. The absence of publicly available patches at the time of this report increases the urgency for mitigation and monitoring.

For European organizations, the impact of CVE-2024-26229 is considerable, especially for those still operating legacy systems such as Windows 10 Version 1809. The vulnerability enables local attackers with limited privileges to escalate their rights, potentially leading to full system compromise. This can result in unauthorized access to sensitive data, disruption of critical services, and the deployment of further malicious payloads or ransomware. Organizations in sectors with high regulatory requirements (e.g., finance, healthcare, government) could face compliance violations and reputational damage if exploited. The vulnerability also poses a risk to operational continuity, as exploitation could cause system crashes or instability. Given that many European enterprises and public sector entities maintain legacy Windows environments for compatibility reasons, the threat is relevant and could be leveraged by insider threats or attackers who gain initial foothold through other means. The lack of known exploits in the wild currently provides a window for proactive defense, but the high severity suggests that exploitation attempts may emerge soon.

1. Immediate prioritization of upgrading or patching affected systems: Although no patch links are provided, organizations should monitor Microsoft’s official security advisories and apply any forthcoming updates promptly. 2. Restrict local access: Limit the number of users with local access rights on Windows 10 Version 1809 systems to reduce the attack surface. 3. Implement application whitelisting and endpoint protection: Use advanced endpoint detection and response (EDR) solutions to detect anomalous behavior indicative of exploitation attempts targeting the CSC service. 4. Harden CSC service permissions and configurations: Review and tighten permissions related to the CSC service to minimize privilege escalation opportunities. 5. Network segmentation: Isolate legacy systems to prevent lateral movement if an attacker exploits this vulnerability. 6. Continuous monitoring and auditing: Enable detailed logging of local privilege escalation attempts and monitor for unusual process behaviors or crashes associated with the CSC service. 7. Plan and execute migration to supported Windows versions: Since Windows 10 Version 1809 is an older release, organizations should accelerate migration to supported versions with active security updates to eliminate exposure to this and similar vulnerabilities.