CVE-2014-6318 in Windows
Summary
by MITRE
The audit logon feature in Remote Desktop Protocol (RDP) in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 does not properly log unauthorized login attempts supplying valid credentials, which makes it easier for remote attackers to bypass intended access restrictions via a series of attempts, aka "Remote Desktop Protocol (RDP) Failure to Audit Vulnerability."
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Analysis
by VulDB Data Team • 12/14/2024
The vulnerability described in CVE-2014-6318 represents a critical flaw in the Remote Desktop Protocol authentication logging mechanism within Microsoft Windows operating systems. This issue affects a wide range of platforms including Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012, and Windows RT. The core problem lies in the audit logon feature's inability to properly record unauthorized login attempts when valid credentials are provided, creating a significant security gap that undermines the intended access controls.
The technical flaw manifests when an attacker attempts to gain unauthorized access through RDP connections using legitimate credentials that may belong to other users or accounts. The vulnerability stems from the insufficient logging of failed authentication attempts, which should normally be recorded in the system's security audit logs. This failure creates a false sense of security for system administrators who rely on these logs to detect suspicious activities and potential brute force attacks. According to CWE-254, this represents a weakness in the authorization mechanism where the system fails to properly track and log unauthorized access attempts, making it difficult to identify malicious activity.
The operational impact of this vulnerability is substantial as it enables attackers to conduct stealthy unauthorized access attempts without leaving proper audit trails. This characteristic makes the vulnerability particularly dangerous because it allows adversaries to perform multiple login attempts without detection, effectively bypassing the intended access restrictions. The vulnerability aligns with ATT&CK technique T1078 which covers legitimate credentials usage, as attackers can exploit this flaw to systematically work through valid credentials without triggering security alerts. This makes it easier for threat actors to conduct prolonged reconnaissance and access attempts that would otherwise be detected through normal audit logging procedures.
The security implications extend beyond simple credential guessing, as this vulnerability can be leveraged in conjunction with other attack vectors to facilitate persistent access to target systems. Attackers can utilize the lack of proper audit logging to conduct automated credential spraying or brute force attacks without fear of immediate detection, making their activities more difficult to trace and investigate. Organizations relying on RDP for remote access management face increased risk of undetected compromise, as the absence of proper logging makes forensic analysis and incident response significantly more challenging. The vulnerability essentially creates a blind spot in the security monitoring infrastructure, allowing malicious actors to operate with reduced risk of detection.
Mitigation strategies should focus on implementing comprehensive monitoring solutions that can detect anomalous RDP usage patterns independent of the flawed audit logging. Network-level controls including firewall rules, RDP port restrictions, and connection rate limiting can help reduce the attack surface. Additionally, implementing multi-factor authentication, disabling unused RDP features, and maintaining strict access control policies can significantly reduce the risk associated with this vulnerability. Regular security assessments and monitoring of RDP connection patterns should be conducted to identify potential abuse of this flaw, as the vulnerability's impact can be mitigated through layered defensive measures that do not rely solely on the compromised audit logging functionality.