CVE-2022-38026: Windows DHCP Client Info Disclosure Flaw

CVE-2022-38026 Overview

CVE-2022-38026 is an information disclosure vulnerability affecting the Windows DHCP Client component across a broad range of Microsoft Windows operating systems. This vulnerability allows a locally authenticated attacker to access sensitive information that should otherwise be protected, potentially exposing confidential data from affected systems.

The vulnerability exists in how the Windows DHCP Client handles certain operations, enabling attackers with low privileges to exploit the flaw without user interaction. Successful exploitation could allow an attacker to read sensitive memory contents or access protected information on the target system.

Critical Impact

Local attackers with low-level access can exploit this vulnerability to disclose sensitive information from Windows DHCP Client operations, potentially exposing confidential system data across both client and server Windows installations.

Affected Products

• Microsoft Windows 10 (multiple versions including 1607, 1809, 20H2, 21H1, 21H2)
• Microsoft Windows 11 (including 22H2 for both ARM64 and x64)
• Microsoft Windows 7 SP1
• Microsoft Windows 8.1
• Microsoft Windows RT 8.1
• Microsoft Windows Server 2008 SP2 and R2 SP1
• Microsoft Windows Server 2012 and R2
• Microsoft Windows Server 2016
• Microsoft Windows Server 2019
• Microsoft Windows Server 2022

Discovery Timeline

• October 11, 2022 - CVE-2022-38026 published to NVD
• January 2, 2025 - Last updated in NVD database

Technical Details for CVE-2022-38026

Vulnerability Analysis

This information disclosure vulnerability resides in the Windows DHCP Client service, a core networking component responsible for obtaining IP addresses and network configuration from DHCP servers. The vulnerability requires local access to the target system, meaning an attacker must already have some level of access to the machine before exploitation is possible.

The attack complexity is low, and the attacker only needs low-level user privileges to exploit the vulnerability. No user interaction is required, making this vulnerability particularly concerning in environments where multiple users share systems or where attackers have gained initial low-privilege footholds.

The impact of successful exploitation is focused entirely on confidentiality—the vulnerability does not allow attackers to modify data or cause system disruption. However, the high confidentiality impact indicates that sensitive information could be exposed, potentially including network configuration data, memory contents, or other protected information handled by the DHCP Client service.

Root Cause

The root cause of CVE-2022-38026 has not been publicly disclosed by Microsoft. The CWE classification of "NVD-CWE-noinfo" indicates that specific technical details about the underlying flaw have not been made available. The vulnerability likely involves improper handling of memory or data within the DHCP Client component that enables unauthorized information access.

Attack Vector

The attack vector for this vulnerability is local, requiring the attacker to have already achieved some level of access to the target system. The exploitation scenario typically involves:

1. An attacker gains initial access to a Windows system with low-privilege credentials
2. The attacker interacts with the DHCP Client service or its associated components
3. Through the vulnerability, the attacker extracts sensitive information that should be protected
4. This information could be used for further attacks or lateral movement within the network

The DHCP Client service (dhcpcsvc.dll) runs on nearly all Windows systems by default, as it manages automatic IP address assignment. This wide deployment increases the potential attack surface.

For detailed technical information about exploitation mechanics, refer to the Microsoft Security Advisory.

Detection Methods for CVE-2022-38026

Indicators of Compromise

• Unusual access patterns to DHCP Client service processes or related system components
• Unexpected queries or operations targeting dhcpcsvc.dll or related DHCP configuration data
• Anomalous local user activity involving network configuration services
• Memory access patterns inconsistent with normal DHCP Client operations

Detection Strategies

• Monitor for suspicious process interactions with the DHCP Client service (svchost.exe hosting dhcpcsvc.dll)
• Implement endpoint detection rules to identify unusual local privilege usage patterns targeting network services
• Deploy SentinelOne Singularity Platform for behavioral analysis of DHCP-related activities
• Enable Windows Security event logging for service and process access auditing

Monitoring Recommendations

• Configure audit policies to log access to DHCP Client service components
• Implement network traffic analysis to detect unusual DHCP-related communications from compromised hosts
• Utilize SentinelOne's real-time monitoring capabilities to detect exploitation attempts
• Review system logs for evidence of information disclosure from network configuration services

How to Mitigate CVE-2022-38026

Immediate Actions Required

• Apply Microsoft security updates released as part of the October 2022 Patch Tuesday
• Prioritize patching on systems where multiple users have local access
• Review and restrict local user privileges where possible
• Deploy endpoint protection solutions capable of detecting post-exploitation activity

Patch Information

Microsoft has released security updates addressing this vulnerability as part of their October 2022 security release cycle. Patches are available for all affected Windows versions through Windows Update, Windows Server Update Services (WSUS), and the Microsoft Update Catalog.

For detailed patch information and download links, refer to the Microsoft Security Update Guide.

Organizations should ensure that automatic updates are enabled or manually apply the relevant security updates to all affected systems. The patches address the underlying vulnerability in the DHCP Client component across all supported Windows versions.

Workarounds

• Limit local access to systems where possible to reduce the attack surface
• Implement the principle of least privilege to minimize the number of users with local system access
• Monitor DHCP Client service activity on critical systems for unusual behavior
• Consider network segmentation to limit the impact of potential information disclosure

# Verify DHCP Client service status and configuration
sc query dhcp
sc qc dhcp

# Review Windows Update status for security patches
wmic qfe list brief /format:table | findstr /i "KB"

# Check system for October 2022 security updates
systeminfo | findstr /i "KB5018410 KB5018411 KB5018418 KB5018419"