CVE-2023-35380: Windows 10 1507 Privilege Escalation Flaw

CVE-2023-35380 Overview

CVE-2023-35380 is a Windows Kernel Elevation of Privilege vulnerability that allows a local attacker with low privileges to escalate their access to gain full system-level control over affected Windows systems. This Use-After-Free (CWE-416) vulnerability in the Windows kernel enables attackers who have already gained initial access to a system to elevate their privileges, potentially leading to complete system compromise.

Critical Impact

Successful exploitation allows attackers to elevate privileges from a low-privileged user context to SYSTEM-level access, enabling complete control over the affected Windows machine including the ability to install programs, view/change/delete data, and create new accounts with full user rights.

Affected Products

• Microsoft Windows 10 (versions 1507, 1607, 1809, 21H2, 22H2)
• Microsoft Windows 11 (versions 21H2, 22H2)
• Microsoft Windows Server 2008 (SP2 and R2 SP1)
• Microsoft Windows Server 2012 (including R2)
• Microsoft Windows Server 2016
• Microsoft Windows Server 2019
• Microsoft Windows Server 2022

Discovery Timeline

• August 8, 2023 - CVE-2023-35380 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2023-35380

Vulnerability Analysis

This Windows Kernel vulnerability is classified as a Use-After-Free (CWE-416) memory corruption issue. Use-After-Free vulnerabilities occur when a program continues to use a pointer after the memory it references has been freed. In the context of the Windows kernel, this type of flaw is particularly dangerous because the kernel operates at the highest privilege level in the operating system.

The vulnerability requires local access to the target system and low-level privileges to exploit. No user interaction is required for exploitation, making it suitable for use in multi-stage attacks where an attacker has already achieved initial code execution through another vector such as phishing or a browser exploit.

Root Cause

The root cause of CVE-2023-35380 is a Use-After-Free condition in the Windows kernel. This occurs when kernel code continues to reference memory that has already been deallocated. When the freed memory is subsequently reallocated for another purpose, the stale pointer can be used to corrupt data structures or execute arbitrary code in kernel mode.

In elevation of privilege scenarios, attackers typically manipulate the timing of memory operations to ensure that the freed memory is reallocated with attacker-controlled data. When the kernel subsequently accesses this memory through the dangling pointer, it operates on the attacker's malicious data structure, enabling privilege escalation.

Attack Vector

The attack vector for CVE-2023-35380 is local, meaning an attacker must already have the ability to execute code on the target system. The typical attack flow involves:

1. Initial Access - Attacker gains low-privilege code execution through phishing, malware, or exploiting another vulnerability
2. Trigger Condition - The attacker crafts specific system calls or operations that trigger the Use-After-Free condition in the kernel
3. Memory Manipulation - Heap spray or other memory manipulation techniques are used to control the contents of the freed memory region
4. Privilege Escalation - When the kernel accesses the corrupted memory, code execution occurs in kernel context, granting SYSTEM privileges

The vulnerability mechanism involves improper memory lifecycle management in the Windows kernel. Attackers who can control the timing of memory allocation and deallocation operations can exploit this condition to escalate from a standard user account to SYSTEM-level privileges. For detailed technical information, refer to the Microsoft Security Update Guide.

Detection Methods for CVE-2023-35380

Indicators of Compromise

• Unusual kernel crash patterns or blue screen events (BSOD) with memory corruption signatures
• Unexpected process execution with SYSTEM-level privileges from low-privileged user contexts
• Memory allocation anomalies detected through kernel debugging tools
• Suspicious syscall patterns targeting kernel memory management functions

Detection Strategies

• Deploy endpoint detection and response (EDR) solutions capable of monitoring kernel-level activity and privilege transitions
• Enable Windows Event Log auditing for privilege escalation events (Event ID 4672, 4673)
• Implement behavioral analytics to detect anomalous process privilege changes
• Use Windows Defender Exploit Guard or similar technologies to detect memory corruption exploitation attempts

Monitoring Recommendations

• Monitor for unusual kernel driver loading activity which may indicate exploitation attempts
• Implement process creation monitoring to detect privilege escalation from user to SYSTEM context
• Enable crash dump analysis to identify potential exploitation attempts that cause system instability
• Deploy SentinelOne agents to provide real-time kernel-level threat detection and automated response capabilities

How to Mitigate CVE-2023-35380

Immediate Actions Required

• Apply the security update from Microsoft immediately on all affected Windows systems
• Prioritize patching of internet-facing systems and critical infrastructure servers
• Implement network segmentation to limit lateral movement if systems cannot be immediately patched
• Review and restrict local user account privileges to minimize the attack surface for privilege escalation

Patch Information

Microsoft has released security updates to address CVE-2023-35380 as part of their August 2023 security update cycle. The patches are available through Windows Update, Microsoft Update Catalog, and Windows Server Update Services (WSUS). Organizations should consult the Microsoft Security Update Guide for CVE-2023-35380 for specific KB article numbers corresponding to each affected Windows version.

Workarounds

• Restrict local logon rights to trusted users only to reduce the potential for exploitation
• Implement application control policies to prevent unauthorized code execution
• Enable Windows Defender Credential Guard to protect against certain privilege escalation techniques
• Use network-level authentication (NLA) for Remote Desktop connections to add an additional authentication layer before exploitation could occur

# Verify Windows Update status
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 20

# Check Windows Defender status
Get-MpComputerStatus | Select-Object AMServiceEnabled, AntispywareEnabled, AntivirusEnabled, RealTimeProtectionEnabled

# Enable auditing for privilege use
auditpol /set /subcategory:"Sensitive Privilege Use" /success:enable /failure:enable