CVE-2022-32230 in Windows
Summary
by MITRE • 06/15/2022
Microsoft Windows SMBv3 suffers from a null pointer dereference in versions of Windows prior to the April, 2022 patch set. By sending a malformed FileNormalizedNameInformation SMBv3 request over a named pipe, an attacker can cause a Blue Screen of Death (BSOD) crash of the Windows kernel. For most systems, this attack requires authentication, except in the special case of Windows Domain Controllers, where unauthenticated users can always open named pipes as long as they can establish an SMB session. Typically, after the BSOD, the victim SMBv3 server will reboot.
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Analysis
by VulDB Data Team • 06/17/2022
The vulnerability identified as CVE-2022-32230 represents a critical null pointer dereference flaw within Microsoft Windows SMBv3 implementation that affects multiple versions of the operating system prior to the April 2022 security updates. This weakness manifests specifically when processing malformed FileNormalizedNameInformation SMBv3 requests transmitted over named pipes, creating a condition where the Windows kernel attempts to access a null memory pointer, resulting in system instability. The technical nature of this vulnerability places it under CWE-476 which specifically addresses null pointer dereference conditions that can lead to application crashes and system instability. The flaw exists in the SMBv3 protocol handler's validation logic for file normalization information requests, where insufficient input sanitization allows malicious payloads to trigger kernel-level memory access violations.
The operational impact of this vulnerability extends beyond simple system crashes to represent a significant denial of service threat that can be exploited to cause complete system outages. The attack requires minimal privileges for most Windows systems, as authenticated users can leverage the vulnerability to force a blue screen of death, effectively rendering the targeted system unavailable to legitimate users. However, the vulnerability exhibits special characteristics on Windows Domain Controllers where the attack can be executed without authentication, as these systems allow unauthenticated users to establish SMB sessions and open named pipes. This makes Domain Controllers particularly vulnerable and attractive targets for attackers seeking to disrupt enterprise network services. The exploitation process involves crafting a malformed SMBv3 request that, when processed by the vulnerable kernel component, triggers the null pointer dereference and subsequent system crash. The resulting BSOD forces the system to reboot automatically, creating a persistent denial of service condition that can be repeatedly exploited to maintain system unavailability.
The security implications of CVE-2022-32230 align with ATT&CK technique T1499.004 which covers network denial of service attacks targeting SMB services. This vulnerability demonstrates how protocol-level flaws can be exploited to create persistent availability issues that impact not just individual systems but entire network infrastructures. Organizations running vulnerable Windows systems face the risk of sustained service disruption, particularly in environments where Domain Controllers are accessible to unauthenticated network users. The vulnerability's exploitation pattern follows established attack methodologies where attackers can systematically target SMB services to create cascading failures across networked systems. The timing of this vulnerability's discovery and patch release coincides with Microsoft's regular monthly security updates, highlighting the importance of timely patch management for maintaining system security. Network administrators should prioritize patching vulnerable systems, particularly Domain Controllers and other critical infrastructure components that may be exposed to unauthenticated network access, as the vulnerability's impact extends beyond simple service disruption to potentially enabling more sophisticated attack vectors through system instability.