CVE-2025-33057 is a vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0) involving a NULL pointer dereference within the Local Security Authority (LSA) component. The LSA is a critical system process responsible for enforcing security policies on the local machine, including authentication and authorization. This vulnerability arises when the LSA improperly handles certain inputs or conditions, leading to a NULL pointer dereference. When exploited, this causes the LSA process to crash, resulting in a denial of service (DoS) condition. The vulnerability requires an attacker with some level of local privileges (PR:L) to execute the attack remotely over the network (AV:N), without requiring user interaction (UI:N). The CVSS v3.1 base score is 6.5, indicating a medium severity level, with the impact confined to availability (A:H) and no direct impact on confidentiality or integrity. The attack complexity is low (AC:L), and the scope remains unchanged (S:U). No known exploits are currently reported in the wild, and no official patches have been linked yet. The vulnerability is categorized under CWE-476 (NULL Pointer Dereference), a common programming error that can lead to crashes or unexpected behavior when dereferencing invalid pointers. Given the nature of the vulnerability, exploitation leads to service disruption rather than data compromise or privilege escalation.

For European organizations, this vulnerability poses a risk primarily to system availability, particularly for those still running Windows 10 Version 1809, which is an older release. A successful exploitation could cause critical systems relying on LSA for authentication to crash or become unresponsive, potentially disrupting business operations, especially in environments with network-exposed Windows 10 endpoints or servers. This could affect services such as remote desktop, authentication services, or any network service dependent on LSA. While the vulnerability does not compromise data confidentiality or integrity, denial of service attacks can lead to operational downtime, impacting productivity and potentially causing cascading failures in dependent systems. Organizations in sectors with high availability requirements, such as finance, healthcare, and critical infrastructure, may experience significant operational impact if exploited. Additionally, since the vulnerability requires some level of local privileges, attackers who have already gained limited access could leverage this flaw to disrupt services further, complicating incident response efforts.

To mitigate this vulnerability, European organizations should prioritize upgrading from Windows 10 Version 1809 to a more recent, supported Windows 10 or Windows 11 version where this issue is resolved. If immediate upgrading is not feasible, organizations should implement network-level protections such as firewall rules to restrict access to LSA-related services and ports from untrusted networks. Employ strict access controls and monitoring to detect and prevent unauthorized local privilege escalation attempts, as the vulnerability requires some level of local privileges. Additionally, organizations should monitor system logs for unexpected LSA crashes or service restarts that could indicate exploitation attempts. Deploying endpoint detection and response (EDR) solutions capable of detecting anomalous process crashes or unusual network activity related to LSA can help in early detection. Finally, maintain a robust patch management process to apply any forthcoming security updates from Microsoft promptly once available.