Remote Code Execution in Windows SMB Client

Successful exploitation can result in remote code execution on a vulnerable Windows system in the context of the SMB client component. Because the flaw affects the client side, exploitation could occur when a vulnerable host connects to or otherwise processes malicious SMB content from an attacker-controlled SMB server or intermediary system. This could allow full compromise of the targeted host, including execution of attacker-supplied code and follow-on actions such as malware deployment, lateral movement, or further intrusion activity, subject to the privileges of the affected process and host configuration.

A documented mitigation is to block TCP port 445 at the network perimeter to reduce the risk of Internet-based exploitation of the SMB client vulnerability. This mitigation is limited: it does not prevent exploitation if a malicious SMB server is reachable from inside the network perimeter or if internal segmentation still permits SMB access to attacker-controlled systems. Additional defensive measures include restricting outbound SMB where operationally feasible and limiting SMB connectivity to trusted hosts.

Apply the Microsoft security updates released for CVE-2022-24500 as part of the April 2022 Patch Tuesday cycle on all supported Windows systems. Prioritize remediation of core operating systems, beginning with public-facing servers, then internal servers, and then client endpoints, while accounting for systems that may initiate SMB connections to untrusted or less-trusted hosts.