CVE-2023-35635 is a medium-severity vulnerability identified in Microsoft Windows 11 version 22H2 (build 10.0.22621.0). It is classified as a CWE-125: Out-of-bounds Read vulnerability within the Windows kernel. This type of vulnerability occurs when the system reads data outside the bounds of allocated memory buffers, which can lead to undefined behavior. In this case, the vulnerability results in a denial of service (DoS) condition, where an attacker can cause the system to crash or become unresponsive by triggering the out-of-bounds read. The CVSS 3.1 base score is 5.5, reflecting a medium severity level. The attack vector is local (AV:L), meaning the attacker must have local access to the system. The attack complexity is low (AC:L), no privileges are required (PR:N), but user interaction is required (UI:R). The impact is limited to availability (A:H), with no impact on confidentiality or integrity. The scope remains unchanged (S:U), indicating the vulnerability affects only the vulnerable component. There are no known exploits in the wild at the time of publication, and no patches have been linked yet. The vulnerability was reserved in June 2023 and published in December 2023. This vulnerability could be leveraged by a local attacker or malicious software to cause system instability or crashes, potentially disrupting business operations or causing data loss due to unexpected shutdowns.

For European organizations, this vulnerability poses a risk primarily to availability of systems running Windows 11 version 22H2. Organizations relying on Windows 11 desktops or workstations could experience denial of service conditions if exploited, leading to operational disruptions. Critical infrastructure sectors, such as finance, healthcare, and government, which often use Windows 11 for end-user computing, may face interruptions in service or productivity losses. Although the vulnerability does not compromise confidentiality or integrity, repeated or targeted exploitation could degrade trust in system stability and increase support and recovery costs. Since exploitation requires local access and user interaction, the threat is more relevant in environments where users might be tricked into executing malicious code or where insider threats exist. Remote exploitation is not feasible, reducing the risk from external attackers. However, organizations with high user mobility or remote work setups should be cautious about potential vectors like malicious documents or applications that could trigger the vulnerability.

To mitigate this vulnerability, European organizations should: 1) Monitor for official Microsoft security updates and apply patches promptly once released, as no patch is currently linked. 2) Implement strict local access controls and user privilege management to limit the ability of untrusted users or processes to execute code locally. 3) Employ application whitelisting and endpoint protection solutions to prevent execution of unauthorized or suspicious software that could exploit this vulnerability. 4) Educate users about the risks of interacting with untrusted files or links that may trigger local exploits requiring user interaction. 5) Use network segmentation to isolate critical systems and reduce the risk of lateral movement by attackers who gain local access. 6) Maintain regular backups and system recovery plans to minimize downtime in case of denial of service incidents. 7) Monitor system logs and crash reports for signs of exploitation attempts to enable early detection and response.