CVE-2002-0644 in SQL Server
Summary
by MITRE
Buffer overflow in several Database Consistency Checkers (DBCCs) for Microsoft SQL Server 2000 and Microsoft Desktop Engine (MSDE) 2000 allows members of the db_owner and db_ddladmin roles to execute arbitrary code.
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Analysis
by VulDB Data Team • 09/14/2025
The vulnerability described in CVE-2002-0644 represents a critical buffer overflow flaw within the Database Consistency Checkers component of Microsoft SQL Server 2000 and MSDE 2000 implementations. This security weakness specifically affects the db_owner and db_ddladmin database roles, which are privileged user groups that possess significant administrative capabilities within database environments. The buffer overflow occurs during the execution of certain database consistency checking operations, creating a potential exploitation vector for malicious actors who have gained access to these elevated privilege accounts.
The technical nature of this vulnerability stems from insufficient input validation within the DBCC functions, which are designed to perform integrity checks on database structures. When maliciously crafted input data is processed by these checkers, the program fails to properly bounds-check the data buffer, leading to memory corruption that can be leveraged to overwrite critical memory locations. This type of flaw falls under the CWE-121 buffer overflow category, which is classified as a critical weakness in data handling and memory management. The vulnerability is particularly dangerous because it operates within the database engine itself, providing attackers with direct access to the underlying system execution environment.
The operational impact of this vulnerability extends beyond simple code execution, as it enables attackers with db_owner or db_ddladmin privileges to potentially escalate their access and compromise entire database systems. These roles typically have extensive control over database objects, schema modifications, and data manipulation capabilities, making them prime targets for attackers seeking persistent access. The exploitation of this vulnerability could lead to unauthorized data access, data corruption, system compromise, and potential lateral movement within network environments where SQL Server instances are deployed. According to ATT&CK framework, this vulnerability maps to T1059 (Command and Scripting Interpreter) and T1068 (Exploitation for Privilege Escalation) tactics, as it allows for command execution and privilege escalation within database contexts.
Organizations with affected systems should prioritize immediate remediation through Microsoft security updates and patches specifically addressing this vulnerability. The mitigation strategy should include comprehensive network segmentation to limit access to database servers, strict enforcement of least privilege principles, and regular security audits of database roles and permissions. Additionally, implementing database activity monitoring and anomaly detection systems can help identify potential exploitation attempts before they result in successful compromises. The vulnerability underscores the importance of maintaining up-to-date security patches and proper access control measures within database environments, as it demonstrates how privileged database roles can become attack vectors when underlying software contains memory corruption flaws.