CVE-2016-3223 in Windows
Summary
by MITRE
Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, and Windows 10 Gold and 1511 mishandle LDAP authentication, which allows man-in-the-middle attackers to gain privileges by modifying group-policy update data within a domain-controller data stream, aka "Group Policy Elevation of Privilege Vulnerability."
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Analysis
by VulDB Data Team • 10/08/2024
This vulnerability resides in the Windows Group Policy processing mechanism within Active Directory environments, specifically affecting versions including Windows Vista SP2 through Windows 10 1511. The flaw stems from improper handling of Lightweight Directory Access Protocol authentication mechanisms during domain controller communication, creating a critical security gap that adversaries can exploit to elevate privileges within network environments. The vulnerability operates through a man-in-the-middle attack vector where attackers positioned within the network can intercept and modify group policy update data streams flowing between domain controllers and client systems. This weakness allows malicious actors to inject malicious group policy objects that can execute arbitrary code with elevated privileges, effectively bypassing standard authentication controls.
The technical implementation of this vulnerability involves the insecure processing of LDAP authentication responses during group policy synchronization processes. When Windows clients receive group policy updates from domain controllers, the system fails to properly validate the integrity of the LDAP data stream, particularly concerning authentication tokens and policy attributes. This lack of proper cryptographic validation enables attackers to manipulate the data without detection, allowing them to modify group policy settings that control user and computer permissions, software installations, and security configurations. The vulnerability specifically affects the way Windows handles authentication contexts within LDAP sessions, creating opportunities for attackers to inject malicious policy data that appears legitimate to the receiving system.
From an operational impact perspective, this vulnerability represents a significant threat to enterprise security infrastructure as it allows attackers to gain unauthorized access to privileged group policy settings that control critical system configurations. Once exploited, adversaries can establish persistent access to network resources by modifying group policies to install backdoors, disable security controls, or create new administrative accounts. The attack requires minimal privileges initially, as the exploit targets the authentication mechanism rather than requiring direct system compromise, making it particularly dangerous for organizations with compromised network access. The vulnerability's impact extends beyond immediate privilege escalation to include potential lateral movement within the domain, as attackers can modify policies to affect multiple systems simultaneously.
Mitigation strategies for this vulnerability should focus on network segmentation and enhanced authentication controls to prevent man-in-the-middle attacks on LDAP communications. Organizations must implement secure LDAP configurations including SSL/TLS encryption for all directory access and ensure proper certificate validation mechanisms are in place. Network administrators should deploy intrusion detection systems to monitor for unusual LDAP traffic patterns and implement strict access controls on domain controller communications. Microsoft released security updates addressing this vulnerability through regular patches, but organizations should also consider implementing additional monitoring controls and network-based protections to detect and prevent exploitation attempts. The remediation process requires careful planning due to the critical nature of group policy functionality, as improper patching or configuration changes could disrupt essential network services and user access. This vulnerability aligns with CWE-310 and follows ATT&CK techniques related to privilege escalation and credential access through network-based attacks, emphasizing the importance of maintaining secure authentication channels within enterprise environments.