CVE-2025-53721 is a high-severity use-after-free vulnerability identified in the Windows Connected Devices Platform Service on Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The vulnerability arises from improper handling of memory, where a program continues to use memory after it has been freed, leading to undefined behavior. In this case, an authorized local attacker can exploit this flaw to elevate privileges on the affected system. The vulnerability requires local access with low privileges and does not require user interaction, but it has a high attack complexity due to the need for specific conditions to trigger the use-after-free. The vulnerability impacts confidentiality, integrity, and availability, as successful exploitation can allow an attacker to execute arbitrary code with elevated privileges, potentially leading to full system compromise. Although no known exploits are currently in the wild, the vulnerability's characteristics make it a significant threat, especially on systems that remain unpatched. The lack of a published patch at the time of disclosure increases the risk for affected users. The CVSS v3.1 base score is 7.0, reflecting high severity with local attack vector, high attack complexity, low privileges required, no user interaction, and full impact on confidentiality, integrity, and availability.

For European organizations, this vulnerability poses a considerable risk, particularly for those still operating legacy systems or Windows 10 Version 1809 in critical environments. Exploitation could allow attackers to escalate privileges locally, bypassing security controls and gaining administrative access. This could lead to unauthorized access to sensitive data, disruption of services, and deployment of further malware or ransomware. Organizations in sectors such as finance, healthcare, government, and critical infrastructure are especially at risk due to the potential for data breaches and operational disruption. The vulnerability's local attack vector means that attackers need some form of initial access, which could be achieved through phishing, insider threats, or exploitation of other vulnerabilities. The absence of known exploits in the wild currently provides a window for proactive mitigation, but the high severity score and potential impact necessitate urgent attention to prevent future exploitation.

Given the absence of an official patch at the time of disclosure, European organizations should implement several specific mitigations beyond generic advice: 1) Restrict local user privileges rigorously, ensuring users operate with the least privilege necessary to reduce the risk of privilege escalation. 2) Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor and block suspicious activities related to the Connected Devices Platform Service. 3) Harden systems by disabling or restricting the Connected Devices Platform Service if it is not required for business operations, thereby reducing the attack surface. 4) Monitor system logs and audit events for unusual behavior indicative of exploitation attempts targeting use-after-free conditions. 5) Prepare for rapid deployment of patches once available by maintaining an up-to-date asset inventory and patch management process focused on legacy Windows versions. 6) Conduct user awareness training to minimize the risk of initial local access vectors such as phishing or social engineering. These targeted mitigations can help reduce the risk until an official patch is released and deployed.