Analysis Summary

Microsoft addressed two serious Active Directory Domain Controller vulnerabilities last month, one of which may be exploited to crash several unpatched Windows servers simultaneously and extend beyond the initial denial-of-service (DoS) attack chain. Experts worry that a lot of firms are still at risk.

Researchers have compiled an analysis of the DoS vulnerability, identified as CVE-2024-49113. This vulnerability was found in Active Directory's Lightweight Directory Access Protocol (LDAP), which searches the databases. It was found alongside a related remote control execution (RCE) flaw, tagged as CVE-2024-49112, which has a CVSS score of 9.8. The Microsoft security update from December included patches for both.

Despite the seriousness and possible consequences of the LDAP vulnerabilities, Microsoft hasn't disclosed many specifics about them, so researchers decided to learn more. The protocol used by workstations and servers in Microsoft Active Directory to get and preserve directory service data is called LDAP. Further examination of the DoS LDAP problem revealed that, provided the target system's domain controller had a DNS server online, a threat actor may utilize the attack chain to accomplish RCE and, worse, to bring down any Windows server.

According to experts, the vulnerability was present in all Windows Server-based organizations until December's Patch Tuesday update. Although there is currently no proof that the vulnerability is being used in the wild, researchers cite the distribution of exploit code as a warning to potential attackers. To get to the major prize, which is the domain controller loaded with credentials, threat actors usually have to make their way from a single compromised device through a maze that researchers liken to a Chutes and Ladders game. The time that these hackers spend attempting to get further access to the system gives defenders the chance to thwart the cyberattack before it gets out of control.

The research also verified that Microsoft's December 2024 updates work, therefore administrators are advised to apply the patches right away to all domain controllers and Windows servers. It is advised to apply compensatory controls, such as LDAP and RPC firewalls, to prevent the exploitation of this vulnerability if servers cannot be patched.

Impact

• Denial of Service
• Unauthorized Access
• Code Execution
• Operational Disruption

Indicators of Compromise

CVE

• CVE-2024-49113
• CVE-2024-49112

Affected Vendors

Remediation

• Use Microsoft Automatic Update to apply the appropriate patch for your system, or the Microsoft Security Update Guide to search for available patches.
• Organizations must test their assets for the vulnerabilities mentioned above and apply the available security patch or mitigation steps as soon as possible.
• Implement multi-factor authentication to add an extra layer of security to login processes.
• Regularly monitor network activity for any unusual behavior, as this may indicate that a cyberattack is underway.
• Organizations must stay vigilant and follow best practices for cybersecurity to protect their systems and data from potential threats. This includes regularly updating software and implementing strong access controls and monitoring tools.
• Develop a comprehensive incident response plan to respond effectively in case of a security breach or data leakage.
• Maintain regular backups of critical data and systems to ensure data recovery in case of a security incident.
• Adhere to security best practices, including the principle of least privilege, and ensure that users and applications have only the necessary permissions.
• Establish a robust patch management process to ensure that security patches are evaluated, tested, and applied promptly.
• Conduct security audits and assessments to evaluate the overall security posture of your systems and networks.
• Implement network segmentation to contain and isolate potential threats to limit their impact on critical systems.