CVE-2023-36802 is a use-after-free vulnerability classified under CWE-416, located in the Microsoft Streaming Service Proxy component of Windows 10 Version 1809 (build 10.0.17763.0). Use-after-free vulnerabilities occur when a program continues to use a pointer after the memory it points to has been freed, potentially leading to arbitrary code execution or privilege escalation. In this case, the vulnerability allows an attacker with low-level privileges on the local machine to elevate their privileges without requiring user interaction, which means no social engineering or user action is necessary. The CVSS 3.1 base score of 7.8 reflects high severity, with attack vector being local (AV:L), low attack complexity (AC:L), requiring privileges (PR:L), and no user interaction (UI:N). The impact metrics indicate high confidentiality, integrity, and availability impacts (C:H/I:H/A:H), meaning a successful exploit could fully compromise the system. The vulnerability was reserved on June 27, 2023, and published on September 12, 2023. No known exploits are currently reported in the wild, but the nature of use-after-free vulnerabilities and the elevation of privilege context make it a critical risk for systems still running this older Windows version. No official patch links are provided yet, suggesting organizations must monitor Microsoft advisories closely. The vulnerability affects legacy Windows 10 systems, which remain in use in many enterprises due to compatibility or upgrade constraints.

For European organizations, the impact of CVE-2023-36802 can be significant, especially for those still operating Windows 10 Version 1809 in production environments. Successful exploitation allows an attacker with limited local access to escalate privileges, potentially gaining SYSTEM-level control. This can lead to unauthorized access to sensitive data, disruption of critical services, and the ability to deploy further malware or ransomware. Sectors such as finance, healthcare, manufacturing, and government, which often have legacy systems, are particularly at risk. The vulnerability could facilitate lateral movement within networks, increasing the risk of widespread compromise. The lack of user interaction requirement lowers the barrier for exploitation once local access is obtained, raising concerns about insider threats or attackers who have gained initial footholds through other means. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, as exploit development could occur rapidly given the vulnerability's nature.

To mitigate CVE-2023-36802, European organizations should prioritize upgrading affected systems from Windows 10 Version 1809 to a supported and patched Windows version, as this version is out of mainstream support and may not receive timely patches. In the absence of an official patch, organizations should implement strict local access controls, ensuring that only trusted users have local login capabilities on vulnerable machines. Employing application whitelisting and endpoint detection and response (EDR) solutions can help detect and prevent suspicious privilege escalation attempts. Network segmentation should be used to limit the impact of a compromised system. Regularly auditing and hardening user privileges to follow the principle of least privilege reduces the attack surface. Monitoring system logs for unusual activity related to the Streaming Service Proxy or privilege escalation attempts is recommended. Organizations should stay alert for Microsoft security updates or advisories that provide patches or workarounds. Finally, educating IT staff about the risks of legacy systems and encouraging timely upgrades is critical.