CVE-1999-0535 in Windows
Summary
by MITRE
A Windows NT account policy for passwords has inappropriate, security-critical settings, e.g. for password length, password age, or uniqueness.
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Analysis
by VulDB Data Team • 04/16/2026
The vulnerability described in CVE-1999-0535 represents a fundamental weakness in Windows nt account policy configuration that directly impacts password security controls. This issue stems from default or improperly configured password policies that fail to enforce adequate security measures for password length, age restrictions, and uniqueness requirements. The flaw exists at the system configuration level where administrative settings do not properly enforce minimum security standards for user authentication credentials.
The technical implementation of this vulnerability involves the Windows nt operating system's account policy enforcement mechanisms that govern password complexity and management parameters. When these policies are inadequately configured, attackers can exploit the weak password controls to gain unauthorized access to systems through brute force attacks, password guessing, or credential reuse attacks. The vulnerability specifically targets the password policy settings that should enforce minimum length requirements, maximum password age limits, and password history restrictions to prevent reuse of previously compromised credentials.
From an operational perspective, this vulnerability creates significant risk exposure for organizations running windows nt systems where default configurations have not been properly hardened. The impact extends beyond individual system compromise to potentially enable lateral movement within networks, privilege escalation attacks, and broader security breaches. Attackers can leverage these weak password policies to systematically target user accounts, especially when combined with other credential-based attack vectors such as password spraying or credential stuffing techniques.
The security implications of this vulnerability align with CWE-521 weakness category which describes weak password requirements and improper password policies. This weakness directly maps to ATT&CK technique T1110.001 which covers password guessing and brute force attacks. Organizations with unpatched systems exhibiting this vulnerability face increased risk of successful credential compromise attacks, particularly in environments where user accounts have default or minimal password complexity requirements.
Mitigation strategies for CVE-1999-0535 require immediate implementation of proper password policy enforcement through group policy objects or local security policies. System administrators must configure minimum password length requirements of at least eight characters, implement maximum password age limits of 90 days or less, and enforce password history restrictions to prevent reuse of previous passwords. Additionally, organizations should implement account lockout policies to prevent automated password guessing attacks and ensure that password complexity requirements are properly enforced through strong password policies that include character set requirements and avoid predictable patterns.
The remediation process involves comprehensive review and hardening of all windows nt systems to ensure that password policies comply with established security standards. This includes regular auditing of password policy configurations, implementation of automated compliance monitoring, and establishment of proper change management procedures for policy modifications. Organizations should also consider implementing additional authentication mechanisms such as multi-factor authentication to provide layered security protection beyond basic password controls. Regular security assessments and vulnerability scanning should be conducted to identify systems that may still be configured with weak password policies, ensuring that the mitigation measures are properly deployed across all affected environments.