CVE-2008-0086 in SQL Server
Summary
by MITRE
Buffer overflow in the convert function in Microsoft SQL Server 2000 SP4, 2000 Desktop Engine (MSDE 2000) SP4, and 2000 Desktop Engine (WMSDE) allows remote authenticated users to execute arbitrary code via a crafted SQL expression.
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Analysis
by VulDB Data Team • 08/12/2019
The vulnerability described in CVE-2008-0086 represents a critical buffer overflow condition within Microsoft SQL Server 2000 and its associated desktop engine variants. This flaw exists specifically within the convert function implementation, which is a fundamental component used for data type conversions within the database management system. The vulnerability affects SQL Server 2000 Service Pack 4 installations as well as MSDE 2000 SP4 and WMSDE configurations, indicating a widespread impact across Microsoft's database server ecosystem from that era. The buffer overflow occurs when processing specially crafted SQL expressions that exploit memory handling inconsistencies in the convert function.
The technical nature of this vulnerability stems from improper bounds checking within the convert function's memory allocation and data processing mechanisms. When an authenticated user submits a malicious SQL expression containing crafted parameters, the system fails to validate the input length against allocated buffer space, allowing memory corruption to occur. This memory corruption can be leveraged to overwrite critical memory locations, potentially including return addresses or function pointers, which enables attackers to redirect program execution flow. The vulnerability requires authentication to exploit, meaning that only users with valid database credentials can initiate the attack, but this limitation does not mitigate the severity of the potential impact.
From an operational perspective, this vulnerability presents a significant risk to database security as it allows remote code execution with the privileges of the database service account. The attack vector operates over network connections to the SQL Server instance, making it particularly dangerous in environments where database servers are accessible from untrusted networks. Successful exploitation can result in complete system compromise, data theft, unauthorized access to sensitive information, and potential lateral movement within the network infrastructure. The vulnerability's classification as a buffer overflow aligns with CWE-121, which specifically addresses stack-based buffer overflow conditions, and it maps to ATT&CK technique T1059.002 for command and scripting interpreter execution.
Organizations should implement immediate mitigations including applying the relevant Microsoft security patches and updates released to address this vulnerability. Network segmentation and access controls should be strengthened to limit exposure of SQL Server instances to untrusted networks. Database administrators should also consider implementing additional monitoring and logging mechanisms to detect anomalous SQL expression patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation and memory management practices in database systems, and serves as a reminder of the critical need for regular security updates and vulnerability management processes. Organizations running legacy SQL Server 2000 systems should consider migrating to supported database versions to avoid similar vulnerabilities and benefit from modern security features and protections.