CVE-2022-38023: 
vulnerability analysis and mitigation

The Netlogon RPC Elevation of Privilege Vulnerability (CVE-2022-38023) was discovered in 2022, affecting the Netlogon Remote Protocol RPC interface which is primarily used to maintain relationships between devices and their domains, as well as among domain controllers and domains. The vulnerability was officially disclosed on November 8, 2022, impacting all domain-joined machine accounts. This security issue specifically relates to weaknesses in the Netlogon protocol when RPC signing is used instead of RPC sealing (Microsoft Support).

The vulnerability stems from the use of RPC signing instead of RPC sealing in the Netlogon protocol. RPC signing only signs the messages sent over the wire, while RPC sealing both signs and encrypts the messages. The implementation may use the rc4-hmac encryption algorithm, which is considered weak and should be avoided. Microsoft implemented a phased approach to address this vulnerability, starting with the initial deployment phase in November 2022, followed by enforcement phases in April 2023, June 2023, and July 2023 (Microsoft Support).

The vulnerability could lead to elevation of privilege if successfully exploited. It affects the security of domain relationships and authentication processes between domain controllers and domain members. The impact is particularly significant as it affects all domain-joined machine accounts in a Windows environment (Microsoft Support).

Microsoft released security updates starting November 8, 2022, to address this vulnerability. The update protects Windows devices by default and operates in Compatibility mode for third-party clients and domain controllers. Organizations can implement stronger security by enabling Enforcement mode through registry settings. The RequireSeal registry subkey can be configured under HKEYLOCALMACHINE\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters to control the security behavior. Microsoft recommends installing the Windows update dated November 8, 2022, or later on all devices, including domain controllers (Microsoft Support).