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). This vulnerability is classified under CWE-416, which pertains to use-after-free errors where a program continues to use memory after it has been freed, potentially leading to arbitrary code execution or privilege escalation. In this case, the flaw allows an authorized local attacker to elevate privileges by exploiting the improper handling of memory within the Connected Devices Platform Service. The attacker must have low-level privileges (PR:L) and no user interaction is required (UI:N) to exploit this vulnerability. The attack complexity is high (AC:H), meaning exploitation requires specific conditions or knowledge, but the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). The vulnerability does not currently have known exploits in the wild, and no official patches or mitigations have been linked yet. The CVSS v3.1 score is 7.0, reflecting a significant risk primarily due to the potential for local privilege escalation, which could allow an attacker to gain SYSTEM-level access, bypass security controls, and execute arbitrary code or manipulate system processes. This vulnerability affects a legacy version of Windows 10 (1809), which is still in use in some environments but is no longer the latest supported version, increasing the risk for organizations that have not updated their systems.

For European organizations, this vulnerability poses a substantial risk, especially in environments where Windows 10 Version 1809 remains deployed, such as in industrial control systems, legacy enterprise applications, or government infrastructure that has delayed upgrades. Successful exploitation could allow attackers to escalate privileges from a low-privileged user account to SYSTEM level, enabling full control over affected machines. This could lead to data breaches, disruption of critical services, installation of persistent malware, or lateral movement within corporate networks. Given the high confidentiality, integrity, and availability impact, sensitive sectors such as finance, healthcare, energy, and public administration in Europe could face severe operational and reputational damage. Although exploitation complexity is high, the lack of required user interaction and the local nature of the attack mean that insider threats or attackers with initial access could leverage this vulnerability effectively. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate it, especially as threat actors often develop exploits rapidly after public disclosure.

European organizations should prioritize identifying and inventorying all systems running Windows 10 Version 1809 to assess exposure. Given the lack of an official patch at the time of this report, organizations should implement strict access controls to limit local user privileges, minimizing the number of users with low-level access that could exploit this vulnerability. Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor for suspicious activity indicative of privilege escalation attempts. Network segmentation should be enforced to contain potential lateral movement from compromised hosts. Organizations should also consider upgrading affected systems to a supported and patched version of Windows 10 or later, as newer versions are less likely to be vulnerable. Regularly review and tighten group policies related to the Connected Devices Platform Service and disable or restrict this service if it is not required for business operations. Finally, maintain heightened monitoring of security logs and alerts for anomalous behavior related to privilege escalation or unusual service activity.