CVE-2022-22037: Windows 10 ALPC Privilege Escalation Flaw

CVE-2022-22037 Overview

CVE-2022-22037 is an elevation of privilege vulnerability affecting the Windows Advanced Local Procedure Call (ALPC) subsystem. Microsoft disclosed the issue in the July 2022 Patch Tuesday cycle. An authenticated local attacker who successfully exploits the flaw can elevate privileges on the target system and obtain code execution at a higher integrity level. The vulnerability impacts every supported Windows client and server release at the time of disclosure, including Windows 10, Windows 11, Windows Server 2019, and Windows Server 2022.

Critical Impact

Successful exploitation grants elevated privileges on the host, enabling full compromise of confidentiality, integrity, and availability on affected Windows systems.

Affected Products

• Microsoft Windows 10, Windows 11, Windows 7 SP1, Windows 8.1, and Windows RT 8.1
• Microsoft Windows Server 2008 SP2, Server 2008 R2 SP1, Server 2012, and Server 2012 R2
• Microsoft Windows Server 2016, Server 2019, and Server 2022

Discovery Timeline

• 2022-07-12 - CVE-2022-22037 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-22037

Vulnerability Analysis

The vulnerability resides in the Windows Advanced Local Procedure Call (ALPC) subsystem. ALPC is a high-performance inter-process communication mechanism used between client processes and subsystem servers running across different privilege boundaries. Many privileged Windows services, including the Local Security Authority Subsystem Service (LSASS), the Service Control Manager (SCM), and RPC endpoints, rely on ALPC ports to receive requests from less-privileged callers.

A flaw in how ALPC handles messages allows a local, authenticated attacker to manipulate the call sequence and trigger privileged behavior in the recipient process. Exploitation grants the attacker the ability to run code in the context of a higher-privileged process. Microsoft assigned the issue an elevation of privilege classification rather than remote code execution.

Root Cause

Microsoft has not published a detailed root-cause writeup, and the CWE is recorded as NVD-CWE-noinfo. Based on the ALPC attack surface and the CVSS metrics, the defect involves improper validation or state handling within the kernel ALPC message processing path. The high attack complexity rating indicates that successful exploitation requires winning a race condition or satisfying specific runtime preconditions.

Attack Vector

Exploitation requires local code execution on the target system as a low-privileged user. The attacker connects to a privileged ALPC port exposed by a system service, then issues a crafted sequence of messages that abuses the flaw to execute code or perform actions in the context of the receiving service. Because ALPC is a core Windows IPC primitive, the vulnerable surface is reachable from standard user sessions without additional privileges.

No verified public proof-of-concept code is available for CVE-2022-22037.
Refer to the Microsoft Security Response Center advisory for vendor guidance:
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-22037

Detection Methods for CVE-2022-22037

Indicators of Compromise

• Unexpected child processes spawned from system services such as services.exe, lsass.exe, or other SYSTEM-context hosts started by a non-administrative user session.
• New or modified scheduled tasks, services, or registry autoruns created shortly after a low-privileged process executes.
• Anomalous token manipulation events where a standard user session begins executing code under NT AUTHORITY\SYSTEM.

Detection Strategies

• Monitor Sysmon Event ID 1 (process creation) and Event ID 10 (process access) for low-integrity processes opening or injecting into SYSTEM-level services.
• Correlate sudden integrity-level transitions from Medium to High or System for the same logon session.
• Hunt for processes that open handles to ALPC ports owned by privileged services followed by privileged file or registry writes.

Monitoring Recommendations

• Forward Windows Security, Sysmon, and kernel audit telemetry to a centralized analytics platform such as SentinelOne Singularity Data Lake for cross-host correlation.
• Enable command-line auditing and PowerShell script block logging on all Windows endpoints to capture post-exploitation activity.
• Track patch deployment status across the fleet and alert on hosts that remain unpatched after the July 2022 cumulative update.

How to Mitigate CVE-2022-22037

Immediate Actions Required

• Apply the Microsoft July 2022 cumulative security update to every affected Windows client and server.
• Prioritize patching on multi-user systems, jump hosts, and domain controllers where local privilege escalation has the largest blast radius.
• Audit local accounts and remove unnecessary interactive logon rights for standard users on sensitive systems.

Patch Information

Microsoft released fixes for CVE-2022-22037 in the July 12, 2022 Patch Tuesday rollups. Administrators should consult the Microsoft Security Update Guide for CVE-2022-22037 for the specific KB article that applies to each Windows build and install it through Windows Update, WSUS, or the Microsoft Update Catalog.

Workarounds

• No official workaround exists. Microsoft directs administrators to install the security update.
• Reduce exposure by enforcing least privilege, restricting local logon, and applying application control policies such as Windows Defender Application Control or AppLocker.
• Deploy a behavioral endpoint protection solution to identify privilege escalation attempts on unpatched hosts until the update is installed.

# Verify the relevant July 2022 cumulative update is installed (PowerShell)
Get-HotFix | Sort-Object -Property InstalledOn -Descending | Select-Object -First 20

# Force a Windows Update scan and install pending security updates
UsoClient StartScan
UsoClient StartDownload
UsoClient StartInstall