CVE-2024-49126: Windows 10 1507 LSASS RCE Vulnerability

CVE-2024-49126 Overview

CVE-2024-49126 is a remote code execution vulnerability in the Windows Local Security Authority Subsystem Service (LSASS), a critical Windows component responsible for enforcing security policies, handling user authentication, and managing access tokens. This vulnerability stems from a use-after-free condition combined with a race condition, allowing remote attackers to execute arbitrary code on affected systems without requiring authentication or user interaction.

LSASS is one of the most sensitive processes on Windows systems, as it manages authentication credentials and security tokens. Successful exploitation of this vulnerability could allow an attacker to gain complete control over the affected system, potentially compromising the entire domain in enterprise environments where domain controllers are targeted.

Critical Impact

Remote attackers can exploit this vulnerability to execute arbitrary code with SYSTEM privileges on affected Windows systems, potentially compromising enterprise authentication infrastructure and enabling lateral movement across networks.

Affected Products

• Microsoft Windows 10 (versions 1507, 1607, 1809, 21H2, 22H2)
• Microsoft Windows 11 (versions 22H2, 23H2, 24H2)
• Microsoft Windows Server 2008, 2008 R2, 2012, 2012 R2, 2016, 2019, 2022, 2022 23H2, 2025

Discovery Timeline

• 2024-12-12 - CVE-2024-49126 published to NVD
• 2025-01-14 - Last updated in NVD database

Technical Details for CVE-2024-49126

Vulnerability Analysis

This vulnerability is classified under CWE-416 (Use After Free) and CWE-362 (Race Condition). The combination of these weakness types creates a particularly dangerous exploitation scenario where attackers can manipulate memory allocation timing to gain control of execution flow.

The LSASS process handles sensitive authentication operations and runs with SYSTEM-level privileges. When a use-after-free condition is triggered through a race condition, an attacker can potentially manipulate freed memory to redirect code execution. The network-accessible nature of LSASS services means this vulnerability can be exploited remotely without requiring prior authentication to the target system.

The exploitation complexity is elevated due to the race condition requirement, meaning attackers must win a timing race to successfully exploit the vulnerability. However, the lack of authentication requirements and user interaction makes this a significant risk for exposed systems.

Root Cause

The vulnerability originates from improper synchronization in memory management operations within the LSASS service. When concurrent operations access shared memory resources, a race condition can occur where memory is freed while still being referenced by another thread. This creates a use-after-free scenario where subsequent operations may interact with reallocated memory, potentially allowing attacker-controlled data to influence program execution.

The combination of CWE-416 (Use After Free) and CWE-362 (Race Condition) indicates that the underlying issue involves both temporal memory safety and thread synchronization failures in the LSASS implementation.

Attack Vector

The attack vector is network-based, allowing remote exploitation without authentication or user interaction. An attacker would need to:

1. Identify a vulnerable Windows system with LSASS services accessible over the network
2. Send specially crafted network requests designed to trigger the race condition
3. Win the race condition to cause a use-after-free state
4. Leverage the memory corruption to execute arbitrary code with SYSTEM privileges

The vulnerability mechanism involves manipulating the timing of concurrent LSASS operations to trigger improper memory handling. Due to the sensitive nature of this vulnerability, specific exploitation details are not publicly available. Security researchers and defenders should refer to the Microsoft Security Update Guide for detailed technical information.

Detection Methods for CVE-2024-49126

Indicators of Compromise

• Unexpected crashes or restarts of the lsass.exe process, which may indicate exploitation attempts
• Anomalous network connections to LSASS-related ports from external or unauthorized sources
• Memory access violations or exception events logged in Windows Event Logs related to LSASS
• Unusual process spawning from lsass.exe that deviates from normal authentication workflows

Detection Strategies

• Monitor Windows Security and System event logs for LSASS-related errors, crashes, or unexpected behavior patterns
• Implement network intrusion detection rules to identify suspicious traffic patterns targeting authentication services
• Deploy endpoint detection and response (EDR) solutions to detect memory manipulation attempts against protected processes
• Use SentinelOne's behavioral AI to identify anomalous LSASS process activity indicative of exploitation attempts

Monitoring Recommendations

• Enable and centralize Windows Event Log collection, focusing on System, Security, and Application logs
• Configure alerts for lsass.exe process termination events (Event ID 1000, 1001 in Application log)
• Implement network segmentation monitoring to detect unauthorized access attempts to domain controllers
• Deploy SentinelOne Singularity Platform for real-time threat detection and autonomous response capabilities

How to Mitigate CVE-2024-49126

Immediate Actions Required

• Apply the December 2024 security updates from Microsoft immediately on all affected Windows systems
• Prioritize patching domain controllers and systems with network-exposed LSASS services
• Implement network segmentation to restrict access to authentication services from untrusted networks
• Enable Credential Guard on supported Windows versions to add additional protection to LSASS

Patch Information

Microsoft has released security updates to address this vulnerability as part of their December 2024 Patch Tuesday release. Organizations should obtain the appropriate patches from the Microsoft Security Update Guide for their specific Windows versions.

The patches should be applied to all affected Windows client and server operating systems, with priority given to:

• Domain controllers
• Systems with externally accessible network services
• Critical infrastructure servers

Workarounds

• Restrict network access to LSASS services using Windows Firewall or network-level access controls
• Enable Windows Defender Credential Guard on Windows 10/11 Enterprise and Server 2016+ to protect LSASS credentials
• Implement strict network segmentation to limit exposure of domain controllers and authentication servers
• Deploy Protected Users security group membership for privileged accounts to reduce credential exposure

# Enable Credential Guard via Group Policy (run on domain controller)
# Navigate to: Computer Configuration > Administrative Templates > System > Device Guard
# Enable "Turn On Virtualization Based Security"
# Set "Credential Guard Configuration" to "Enabled with UEFI lock"

# Alternatively, enable via registry (requires reboot)
reg add "HKLM\SYSTEM\CurrentControlSet\Control\DeviceGuard" /v EnableVirtualizationBasedSecurity /t REG_DWORD /d 1 /f
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Lsa" /v LsaCfgFlags /t REG_DWORD /d 1 /f