CVE-2024-49127 Overview
CVE-2024-49127 is a remote code execution vulnerability in the Windows Lightweight Directory Access Protocol (LDAP) service. This vulnerability arises from improper handling of memory operations combined with race condition flaws, potentially allowing an unauthenticated attacker to execute arbitrary code on affected systems over the network.
Critical Impact
Successful exploitation could allow remote attackers to execute arbitrary code with elevated privileges on Domain Controllers and other Windows systems running LDAP services, potentially compromising entire Active Directory environments.
Affected Products
- Microsoft Windows 10 (versions 1507, 1607, 1809, 21H2, 22H2)
- Microsoft Windows 11 (versions 22H2, 23H2, 24H2)
- Microsoft Windows Server 2008, 2012, 2016, 2019, 2022, 2022 23H2, and 2025
Discovery Timeline
- 2024-12-12 - CVE-2024-49127 published to NVD
- 2025-01-14 - Last updated in NVD database
Technical Details for CVE-2024-49127
Vulnerability Analysis
This vulnerability affects the Windows LDAP implementation and is classified under CWE-416 (Use After Free) and CWE-362 (Race Condition). The combination of these weakness types indicates a complex vulnerability where improper synchronization during memory operations can lead to a use-after-free condition. When the LDAP service processes specially crafted requests, a race condition may allow an attacker to manipulate memory that has already been freed, leading to arbitrary code execution.
The network-based attack vector makes this particularly concerning for enterprise environments where LDAP services, especially on Domain Controllers, are often exposed to internal networks. The vulnerability requires no authentication or user interaction, meaning any attacker with network access to the LDAP service could potentially exploit it.
Root Cause
The root cause of CVE-2024-49127 stems from two interrelated issues in the Windows LDAP service:
Use After Free (CWE-416): The LDAP service fails to properly manage memory lifecycle during certain operations, allowing references to freed memory blocks to persist and be subsequently accessed.
Race Condition (CWE-362): Concurrent operations within the LDAP service lack proper synchronization mechanisms, creating timing windows where memory states can become inconsistent between the time of check and time of use.
When these conditions are exploited in combination, an attacker can manipulate the memory state to achieve code execution.
Attack Vector
The attack is network-based and can be executed remotely without authentication. An attacker would need to:
- Establish a network connection to a vulnerable Windows LDAP service (typically port 389 for LDAP or port 636 for LDAPS)
- Send specially crafted LDAP requests designed to trigger the race condition
- Time the requests to exploit the use-after-free vulnerability
- Achieve code execution in the context of the LDAP service
While the attack complexity is considered high due to the need to win the race condition, successful exploitation would result in complete compromise of confidentiality, integrity, and availability. The vulnerability is particularly dangerous in Active Directory environments where Domain Controllers run LDAP services and hold critical authentication data.
Detection Methods for CVE-2024-49127
Indicators of Compromise
- Unusual LDAP connection patterns or high volumes of malformed LDAP requests to Domain Controllers
- Unexpected process crashes or restarts of the LDAP service (lsass.exe on Domain Controllers)
- Memory corruption artifacts or crash dumps indicating use-after-free conditions in LDAP-related processes
- Suspicious code execution events originating from LDAP service context
Detection Strategies
- Monitor LDAP service logs for anomalous request patterns, particularly rapid successive requests that could indicate race condition exploitation attempts
- Implement network intrusion detection rules to identify malformed or suspicious LDAP traffic targeting ports 389 and 636
- Deploy endpoint detection solutions to monitor for unexpected behavior in lsass.exe and related LDAP components
- Utilize SentinelOne's behavioral AI to detect exploitation attempts through memory corruption pattern recognition
Monitoring Recommendations
- Enable advanced LDAP diagnostics logging on Domain Controllers to capture detailed request information
- Configure SIEM correlation rules to alert on patterns consistent with exploitation attempts
- Implement network segmentation monitoring to detect unauthorized LDAP access from unexpected network segments
- Regularly review security event logs for authentication anomalies following potential exploitation
How to Mitigate CVE-2024-49127
Immediate Actions Required
- Apply the December 2024 security updates from Microsoft to all affected Windows systems immediately, prioritizing Domain Controllers
- Implement network segmentation to restrict LDAP access to only authorized clients and systems
- Consider temporarily blocking external access to LDAP ports (389, 636) if not required for business operations
- Enable LDAP channel binding and LDAP signing to add additional layers of protection
Patch Information
Microsoft has released security updates addressing this vulnerability as part of the December 2024 Patch Tuesday release. Detailed patch information and downloads are available through the Microsoft Security Response Center. Organizations should prioritize patching Domain Controllers and other systems running LDAP services.
Workarounds
- Restrict network access to LDAP services using firewall rules to limit exposure to trusted networks only
- Implement LDAP signing and channel binding requirements through Group Policy to harden LDAP communications
- Deploy network-based intrusion prevention systems to detect and block exploitation attempts
- Consider using IPSec policies to authenticate and encrypt LDAP traffic between authorized clients and servers
# Enable LDAP signing via Group Policy (requires domain admin)
# Navigate to: Computer Configuration > Policies > Windows Settings > Security Settings > Local Policies > Security Options
# Set "Domain controller: LDAP server signing requirements" to "Require signing"
# PowerShell command to verify LDAP signing status
Get-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\NTDS\Parameters" -Name "LDAPServerIntegrity"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
