CVE-2025-48815 is a high-severity vulnerability classified as CWE-843 (Access of Resource Using Incompatible Type, commonly known as 'type confusion') affecting Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The vulnerability resides in the Windows SSDP (Simple Service Discovery Protocol) Service, a component responsible for network device discovery and communication. Due to improper handling of data types within this service, an authorized local attacker can exploit type confusion to access resources incorrectly, leading to privilege escalation. Specifically, the attacker with limited privileges on the system can leverage this flaw to gain higher privileges, potentially SYSTEM-level, without requiring user interaction. The CVSS v3.1 base score is 7.8, indicating a high impact on confidentiality, integrity, and availability. The attack vector is local (AV:L), requiring low attack complexity (AC:L) and privileges (PR:L), but no user interaction (UI:N). The vulnerability scope is unchanged (S:U), meaning the impact is confined to the vulnerable component or system. Although no known exploits are currently reported in the wild, the vulnerability's nature and severity make it a significant risk, especially in environments where Windows 10 Version 1809 remains in use. The lack of published patches at the time of this report increases exposure. Given that SSDP is a core network service, exploitation could allow attackers to bypass security controls and execute arbitrary code or commands with elevated privileges, potentially leading to full system compromise.

For European organizations, this vulnerability poses a substantial risk, particularly for those still operating legacy Windows 10 Version 1809 systems, which may be common in industrial, governmental, or enterprise environments with slower upgrade cycles. Successful exploitation could allow attackers to elevate privileges locally, enabling lateral movement, installation of persistent malware, or disruption of critical services. Confidentiality is at risk as attackers could access sensitive data; integrity could be compromised through unauthorized changes; and availability could be impacted by service disruption or system instability. Organizations in sectors such as finance, healthcare, manufacturing, and critical infrastructure, which often rely on Windows-based systems, may face increased risk of targeted attacks or insider threats exploiting this vulnerability. The local attack vector means that attackers need some form of access to the system, which could be achieved via phishing, physical access, or leveraging other vulnerabilities to gain initial foothold. The absence of user interaction requirement facilitates automated exploitation once local access is obtained. The vulnerability could also be chained with other exploits to escalate privileges and achieve full system control, amplifying its impact on European enterprises.

Given the absence of an official patch at the time of this report, European organizations should implement immediate compensating controls. First, restrict local access to systems running Windows 10 Version 1809 by enforcing strict access controls and monitoring for unauthorized logins. Disable or restrict the Windows SSDP Service where feasible, especially on systems that do not require network device discovery functionality. Employ application whitelisting and endpoint detection and response (EDR) solutions to detect unusual privilege escalation attempts or anomalous behavior related to SSDP. Conduct thorough audits to identify all systems running the affected Windows version and prioritize their upgrade to a supported and patched Windows version as soon as updates become available. Network segmentation can limit the spread of an attacker who gains local access. Additionally, implement strict user privilege management to minimize the number of users with local access rights. Regularly review and update intrusion detection systems (IDS) and security information and event management (SIEM) rules to flag suspicious activities related to SSDP or privilege escalation attempts. Finally, educate IT staff about this vulnerability and the importance of rapid patching once Microsoft releases an official fix.