CVE-2022-35750: Windows 10 1507 Privilege Escalation Flaw

CVE-2022-35750 Overview

CVE-2022-35750 is an elevation of privilege vulnerability in the Win32k kernel-mode driver, a core component of the Windows graphics subsystem. This vulnerability allows a local attacker with low privileges to escalate their access to SYSTEM-level permissions on affected Windows systems. The Win32k driver handles critical graphical operations and user interface rendering, making it a high-value target for privilege escalation attacks.

Critical Impact

Successful exploitation enables local attackers to gain SYSTEM privileges, allowing complete control over affected Windows systems including the ability to install programs, modify data, and create accounts with full user rights.

Affected Products

• Microsoft Windows 10 (versions 1507, 1607, 1809, 20H2, 21H1)
• Microsoft Windows 11 21H2
• Microsoft Windows 7 SP1
• Microsoft Windows 8.1 and Windows RT 8.1
• Microsoft Windows Server 2008 SP2, 2008 R2 SP1, 2012, 2012 R2, 2016, 2019, 2022, and 20H2

Discovery Timeline

• 2023-05-31 - CVE-2022-35750 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-35750

Vulnerability Analysis

The Win32k elevation of privilege vulnerability exists within the Windows kernel-mode driver win32k.sys, which is responsible for managing windows, screen output, input, and graphics operations. This driver operates at kernel level (Ring 0), making any security flaws particularly dangerous as they provide direct access to the most privileged execution context in Windows.

The vulnerability allows an authenticated attacker who has already gained initial access to a system to escalate their privileges from a standard user account to SYSTEM level. This type of attack typically occurs after an initial compromise, where attackers leverage privilege escalation vulnerabilities to bypass User Account Control (UAC) and other security boundaries.

Win32k vulnerabilities are frequently exploited in the wild due to the driver's complex codebase, extensive attack surface, and the high value of the privileges that can be obtained through successful exploitation.

Root Cause

The root cause of CVE-2022-35750 has not been publicly disclosed in detail by Microsoft beyond categorizing it as an elevation of privilege issue. Win32k vulnerabilities commonly stem from improper handling of window objects, callback functions, or memory management operations within the kernel-mode driver. These issues can lead to conditions where an attacker can manipulate kernel memory or execute code in the kernel context.

Attack Vector

The attack vector for CVE-2022-35750 is local, meaning an attacker must already have the ability to execute code on the target system. The attack requires low privileges to initiate but no user interaction, making it suitable for use in post-exploitation scenarios. A typical attack chain would involve:

1. Initial access through phishing, malware, or exploitation of another vulnerability
2. Execution of a malicious application or script that triggers the Win32k vulnerability
3. Escalation to SYSTEM privileges, bypassing security controls
4. Full system compromise with the ability to perform any administrative action

Due to the local attack vector and low complexity requirements, this vulnerability is particularly dangerous in environments where attackers may already have limited access to systems.

Detection Methods for CVE-2022-35750

Indicators of Compromise

• Unusual processes running with SYSTEM privileges that originate from standard user sessions
• Suspicious Win32k-related crash dumps or kernel exceptions in system event logs
• Presence of exploit code or privilege escalation tools in user-accessible directories
• Anomalous system call patterns targeting win32k.sys functions

Detection Strategies

• Monitor for unexpected privilege escalation events in Windows Security Event Logs (Event ID 4672, 4673)
• Deploy endpoint detection and response (EDR) solutions to detect kernel exploitation attempts
• Implement behavioral analysis to identify processes that spawn child processes with elevated privileges unexpectedly
• Use SentinelOne's Behavioral AI engine to detect exploit techniques targeting Win32k vulnerabilities

Monitoring Recommendations

• Enable enhanced audit logging for privilege use and process creation events
• Configure Windows Defender Exploit Guard with Attack Surface Reduction rules targeting kernel exploitation
• Review Event ID 1000 and 1001 in Application logs for win32k.sys-related crashes that may indicate exploitation attempts
• Implement sysmon with appropriate configuration to track process creation with parent-child relationships

How to Mitigate CVE-2022-35750

Immediate Actions Required

• Apply the security updates provided by Microsoft as part of the August 2022 Patch Tuesday release
• Prioritize patching on systems where users have local access or where the risk of initial compromise is elevated
• Review and restrict local user privileges to minimize the impact of potential exploitation
• Enable SentinelOne's real-time protection to detect and block privilege escalation attempts

Patch Information

Microsoft has released security updates addressing CVE-2022-35750 for all affected Windows versions. Organizations should consult the Microsoft Security Update Guide for CVE-2022-35750 for specific KB article numbers and download links for their Windows versions. Updates are available through Windows Update, WSUS, and the Microsoft Update Catalog.

Workarounds

• Restrict local logon access to trusted users only on critical systems
• Implement application whitelisting to prevent unauthorized code execution
• Deploy network segmentation to limit lateral movement if an attacker gains initial access
• Consider using Windows Defender Credential Guard and other virtualization-based security features where supported

# Example: Check Windows Update for available security patches
# Run in elevated PowerShell
Get-WindowsUpdate -KBArticleID "KB*" | Where-Object {$_.Title -match "2022-35750"}

# Verify current system patch level
wmic qfe list | findstr /i "Security"