CVE-2000-0402 in SQL Server
Summary
by MITRE
The Mixed Mode authentication capability in Microsoft SQL Server 7.0 stores the System Administrator (sa) account in plaintext in a log file which is readable by any user, aka the "SQL Server 7.0 Service Pack Password" vulnerability.
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Analysis
by VulDB Data Team • 06/01/2025
The vulnerability identified as CVE-2000-0402 represents a critical security flaw in Microsoft SQL Server 7.0 that fundamentally undermines the authentication mechanisms of the database system. This weakness specifically affects the Mixed Mode authentication feature which allows both Windows authentication and SQL Server authentication methods to coexist within the same system. The vulnerability stems from the improper handling of privileged account credentials during the service startup process, creating a persistent security risk that has significant implications for database security posture.
The technical flaw manifests when the SQL Server 7.0 service attempts to authenticate the System Administrator (sa) account, which is stored in plaintext within a log file that lacks proper access controls. This log file becomes accessible to any user with sufficient privileges to read system files, effectively providing unauthorized access to the highest privileged account within the database system. The vulnerability exists because the authentication process fails to properly encrypt or obfuscate the sa account credentials during their temporary storage in the logging mechanism, creating a direct pathway for credential compromise that aligns with CWE-312 (CWE-312: Cleartext Storage of Sensitive Information).
The operational impact of this vulnerability extends far beyond simple credential exposure, as it provides attackers with a direct route to achieve complete administrative control over the affected SQL Server instance. Once an attacker gains access to the plaintext credentials stored in the log file, they can execute any administrative function within the database environment, including data manipulation, schema changes, user privilege modifications, and potentially lateral movement to other systems within the network. This vulnerability particularly affects organizations running SQL Server 7.0 in Mixed Mode authentication environments where the sa account is actively used for administrative purposes, making it a prime target for exploitation in database-centric attacks.
The security implications of CVE-2000-0402 align with several ATT&CK framework techniques including T1003 (OS Credential Dumping) and T1078 (Valid Accounts) as it enables adversaries to obtain legitimate administrative credentials through the exploitation of improperly protected log files. Organizations implementing this vulnerability in their database infrastructure face a significant risk of data breaches, as the sa account typically possesses unrestricted access to all database objects and can bypass many security controls designed to limit administrative access. The vulnerability demonstrates a fundamental failure in the principle of least privilege and proper credential management, creating a persistent backdoor that remains active until the system is properly patched or the log file is secured.
Mitigation strategies for this vulnerability primarily focus on immediate patching of the affected SQL Server 7.0 installations with the appropriate service pack updates that address the plaintext credential storage issue. Organizations should also implement strict access controls on system log files, particularly those containing authentication-related information, and consider disabling Mixed Mode authentication where possible in favor of Windows authentication methods. Additionally, regular monitoring of system logs for unauthorized access attempts and implementing proper credential rotation policies can help reduce the risk exposure associated with this vulnerability. The remediation process should include comprehensive security audits of database environments to identify other potential credential exposure points and ensure that similar vulnerabilities are not present in other system components.