CVE-2025-27730 is a high-severity use-after-free vulnerability (CWE-416) found in the Windows Digital Media component of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). This vulnerability allows an authorized local attacker to elevate privileges on the affected system. Use-after-free vulnerabilities occur when a program continues to use a pointer after the memory it points to has been freed, leading to undefined behavior such as memory corruption, crashes, or execution of arbitrary code. In this case, the flaw resides within the Windows Digital Media subsystem, which handles media-related operations. Exploiting this vulnerability requires local access with some level of privileges (low privileges), but no user interaction is needed once the attacker has access. The CVSS v3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability, with low attack complexity and no user interaction required. The vulnerability does not currently have known exploits in the wild, but its presence in an older Windows 10 version that is still in use means it poses a significant risk if left unpatched. No official patch links are provided yet, indicating that mitigation may rely on workarounds or system upgrades until a fix is released. The vulnerability was reserved in early March 2025 and published in April 2025, showing recent discovery and disclosure.

For European organizations, this vulnerability poses a significant risk especially in environments where Windows 10 Version 1809 is still deployed, such as legacy systems or specialized industrial setups. Successful exploitation can lead to local privilege escalation, allowing attackers who have gained limited access (e.g., via phishing, compromised accounts, or insider threats) to gain SYSTEM-level privileges. This can facilitate further lateral movement, data exfiltration, installation of persistent malware, or disruption of critical services. Confidentiality, integrity, and availability of sensitive data and systems could be severely compromised. Given the high CVSS score and the nature of the vulnerability, organizations with compliance requirements (GDPR, NIS Directive) must be particularly vigilant. The lack of known exploits in the wild reduces immediate risk but does not eliminate it, as attackers may develop exploits rapidly once details become public. The threat is more acute in sectors with high-value targets such as finance, healthcare, government, and critical infrastructure within Europe.

1. Immediate mitigation should focus on upgrading affected systems to a supported and patched version of Windows, ideally beyond Windows 10 Version 1809, as this version is out of mainstream support and may not receive timely patches. 2. If upgrading is not immediately feasible, restrict local access to affected systems by enforcing strict access controls, limiting administrative privileges, and using application whitelisting to prevent unauthorized code execution. 3. Employ endpoint detection and response (EDR) solutions to monitor for suspicious activity indicative of privilege escalation attempts. 4. Regularly audit and review user accounts and permissions to minimize the number of users with local access rights. 5. Implement network segmentation to isolate legacy systems and reduce the attack surface. 6. Monitor vendor announcements closely for official patches or workarounds and apply them promptly once available. 7. Educate users and administrators about the risks of local privilege escalation vulnerabilities and the importance of maintaining updated systems.