CVE-2002-0056 in SQL Server
Summary
by MITRE
Buffer overflow in SQL Server 7.0 and 2000 allows remote attackers to execute arbitrary code via a long OLE DB provider name to (1) OpenDataSource or (2) OpenRowset in an ad hoc connection.
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Analysis
by VulDB Data Team • 12/30/2024
The vulnerability described in CVE-2002-0056 represents a critical buffer overflow flaw affecting Microsoft SQL Server versions 7.0 and 2000. This security weakness resides in the database engine's handling of OLE DB provider names within specific administrative functions, creating a pathway for remote code execution that could be exploited by malicious actors without authentication. The vulnerability specifically targets the OpenDataSource and OpenRowset functions that are commonly used in ad hoc database connections, making it particularly dangerous in environments where these operations are frequently performed. The buffer overflow occurs when an attacker supplies an excessively long provider name string that exceeds the allocated memory buffer, causing memory corruption that can be leveraged to execute arbitrary code with the privileges of the SQL Server process.
This vulnerability directly maps to CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The flaw operates at the application layer within the SQL Server engine's connection handling mechanisms, where the system fails to properly validate the length of incoming OLE DB provider names before processing them. The attack vector is entirely remote, meaning that an unauthenticated attacker can exploit this vulnerability from outside the network boundary, potentially compromising entire database servers. The operational impact is severe as successful exploitation would allow attackers to execute code with elevated privileges, potentially leading to full system compromise, data exfiltration, or lateral movement within the network infrastructure. The vulnerability affects both SQL Server 7.0 and 2000 versions, representing a significant attack surface across multiple generations of the database platform.
The exploitation of this vulnerability aligns with techniques documented in the MITRE ATT&CK framework under the Tactic of Execution and Privilege Escalation, where adversaries leverage application-level vulnerabilities to gain unauthorized code execution. The attack typically involves crafting a specially formatted SQL command that includes an overly long OLE DB provider name, which when processed by the vulnerable SQL Server functions triggers the buffer overflow condition. This type of vulnerability is particularly concerning because it can be exploited through standard database connection protocols without requiring any specialized tools or prior access to the system. Organizations running these legacy SQL Server versions face significant risk as the vulnerability remains exploitable even in modern network environments where database servers may be exposed to external traffic. The memory corruption resulting from this buffer overflow can be manipulated to redirect program execution flow, potentially allowing attackers to inject and execute malicious code payloads that could establish persistent access or perform destructive operations on the database infrastructure.
Mitigation strategies for this vulnerability should focus on immediate patching of affected SQL Server installations, as Microsoft released security updates specifically addressing this issue in their regular security bulletins. Organizations should implement network segmentation to limit access to SQL Server instances, restrict database connection permissions, and disable unnecessary database functions that could be exploited. The principle of least privilege should be enforced by ensuring that database accounts have minimal required permissions, reducing the potential impact if exploitation occurs. Network monitoring and intrusion detection systems should be configured to detect unusual database connection patterns or SQL command structures that might indicate exploitation attempts. Additionally, implementing proper input validation at application layers that interact with SQL Server can provide additional defense-in-depth measures, though the primary mitigation remains the application of official security patches. Organizations should also consider upgrading to supported SQL Server versions, as versions 7.0 and 2000 have reached end-of-life and no longer receive security updates from Microsoft.