CVE-2016-3352 in Windows
Summary
by MITRE
Microsoft Windows 8.1, Windows RT 8.1, and Windows 10 Gold, 1511, and 1607 do not properly check NTLM SSO requests for MSA logins, which makes it easier for remote attackers to determine passwords via a brute-force attack on NTLM password hashes, aka "Microsoft Information Disclosure Vulnerability."
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Analysis
by VulDB Data Team • 09/16/2022
This vulnerability resides in Microsoft Windows operating systems including Windows 8.1, Windows RT 8.1, and Windows 10 versions 1511 and 1607. The core issue stems from improper validation of NTLM Single Sign-On requests specifically for Microsoft Account logins, creating a significant information disclosure weakness that directly impacts authentication security. The flaw allows remote attackers to exploit the authentication mechanism by targeting NTLM password hashes through brute-force techniques, fundamentally undermining the security posture of affected systems.
The technical implementation of this vulnerability involves the Windows authentication subsystem failing to properly validate NTLM SSO requests when Microsoft Accounts are used for login. This occurs because the system does not adequately verify the authenticity of the authentication requests, enabling attackers to conduct systematic brute-force attacks against the NTLM password hashes. The vulnerability is particularly dangerous because it operates at the authentication protocol level, where the system should be enforcing strict validation mechanisms but instead allows potentially malicious requests to proceed unchecked.
From an operational impact perspective, this vulnerability creates a substantial risk for organizations using affected Windows versions, as it provides attackers with a direct pathway to compromise user credentials through password hash brute-forcing. The weakness essentially weakens the entire authentication infrastructure by making it significantly easier for attackers to determine valid passwords, potentially leading to unauthorized system access, privilege escalation, and lateral movement within networks. Security professionals must recognize that this vulnerability can be exploited remotely without requiring elevated privileges, making it particularly attractive to threat actors.
The vulnerability maps directly to CWE-200, which addresses "Information Exposure," and aligns with ATT&CK technique T1110.003 for "Brute Force: Password Guessing." Organizations should implement immediate mitigations including disabling NTLM authentication where possible, implementing account lockout policies, and deploying intrusion detection systems to monitor for unusual authentication patterns. Additionally, organizations must ensure proper patch management processes are in place to address this vulnerability promptly, as the window of exploitation remains significant due to the widespread deployment of affected Windows versions. The remediation strategy should include comprehensive network monitoring and authentication auditing to detect potential exploitation attempts and ensure complete system hardening against similar authentication bypass vulnerabilities.