CVE-2024-30067 is an elevation of privilege vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The root cause is an integer overflow or wraparound condition (CWE-190) within the Winlogon component, a critical system process responsible for handling user logins and session management. An integer overflow occurs when an arithmetic operation attempts to create a numeric value that is outside the range that can be represented with a given number of bits, potentially causing unexpected behavior such as buffer overflows or logic errors. In this case, the overflow can lead to improper handling of memory or security checks, allowing a local attacker with limited privileges (low-level privileges) to escalate their rights to higher privileges without requiring user interaction. The vulnerability has a CVSS 3.1 base score of 5.5, indicating a medium severity level. The attack vector is local (AV:L), requiring the attacker to have some level of access to the system already, and the complexity is low (AC:L), meaning exploitation does not require complex conditions. No user interaction is needed (UI:N), and the scope remains unchanged (S:U). The impact affects integrity (I:H) but not confidentiality or availability, meaning the attacker can modify or manipulate system state or data but not necessarily read sensitive information or cause denial of service. There are no known exploits in the wild at the time of publication, and no official patches have been linked yet. This vulnerability is particularly concerning because Winlogon is a core component of Windows security, and elevation of privilege flaws can be leveraged by attackers to gain administrative control, bypass security controls, and persist on systems.

For European organizations, this vulnerability poses a significant risk primarily to systems still running Windows 10 Version 1809, which, despite being an older release, may remain in use in certain enterprise environments due to legacy application dependencies or delayed upgrade cycles. Successful exploitation allows a local attacker to escalate privileges, potentially enabling them to install malware, disable security controls, or move laterally within the network. This can lead to compromised integrity of critical systems and data, undermining trust in IT infrastructure. Sectors with stringent regulatory requirements such as finance, healthcare, and government agencies could face compliance risks if attackers exploit this vulnerability to manipulate sensitive data or system configurations. Although the vulnerability does not directly impact confidentiality or availability, the elevated privileges gained can be a stepping stone for further attacks, including data exfiltration or ransomware deployment. The lack of required user interaction and low complexity of exploitation increase the likelihood of successful attacks in environments where local access is possible, such as shared workstations or multi-user systems.

Given the absence of an official patch at the time of analysis, European organizations should prioritize the following mitigations: 1) Restrict local access to systems running Windows 10 Version 1809 by enforcing strict access controls and limiting user privileges to the minimum necessary. 2) Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor and block suspicious activities related to privilege escalation attempts. 3) Conduct thorough audits of user accounts and remove or disable unnecessary local accounts to reduce the attack surface. 4) Implement network segmentation to isolate legacy systems and limit lateral movement opportunities. 5) Prepare for rapid deployment of patches once available by maintaining an up-to-date asset inventory and patch management process. 6) Educate IT staff and users about the risks of local privilege escalation and the importance of reporting unusual system behavior. 7) Consider upgrading affected systems to a supported Windows version where this vulnerability is not present or has been remediated.