CVE-2000-1085 in SQL Server
Summary
by MITRE
The xp_peekqueue function in Microsoft SQL Server 2000 and SQL Server Desktop Engine (MSDE) does not properly restrict the length of a buffer before calling the srv_paraminfo function in the SQL Server API for Extended Stored Procedures (XP), which allows an attacker to cause a denial of service or execute arbitrary commands, aka the "Extended Stored Procedure Parameter Parsing" vulnerability.
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Analysis
by VulDB Data Team • 03/27/2025
The xp_peekqueue function in Microsoft SQL Server 2000 and SQL Server Desktop Engine represents a critical security flaw that stems from improper buffer length validation within the extended stored procedures API. This vulnerability exists in the server-side execution environment where the srv_paraminfo function is invoked without adequate bounds checking on input parameters, creating a pathway for malicious exploitation. The flaw resides in the fundamental design of how parameter parsing occurs within the extended stored procedure interface, specifically when processing queue-related operations through the xp_peekqueue functionality.
This buffer overflow condition manifests when an attacker crafts specially formatted input parameters that exceed the allocated buffer space within the srv_paraminfo function call. The vulnerability classifies under CWE-121 as a stack-based buffer overflow, where insufficient input validation allows memory corruption that can be leveraged for privilege escalation or denial of service attacks. The attack surface extends across all systems running SQL Server 2000 or MSDE versions that utilize this extended stored procedure functionality, making it particularly dangerous in enterprise environments where these older systems may still be operational.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable arbitrary code execution with the privileges of the SQL Server service account. Attackers can exploit this weakness to execute malicious payloads that may escalate privileges, access sensitive data, or disrupt database operations. The vulnerability's exploitation requires minimal privileges since it targets the extended stored procedure interface rather than requiring direct database access or administrative credentials. This makes it particularly concerning for environments where SQL Server service accounts have elevated permissions or where the database server hosts critical business applications.
Mitigation strategies should focus on immediate patching of affected systems with Microsoft security updates, though organizations may need to implement network segmentation to limit access to SQL Server instances. The ATT&CK framework categorizes this vulnerability under T1210 - Exploitation of Remote Services, with specific techniques involving T1059 - Command and Scripting Interpreter and T1068 - Exploitation for Privilege Escalation. Organizations should also consider implementing proper input validation controls, disabling unnecessary extended stored procedures, and conducting regular security assessments of legacy database systems. Additionally, monitoring for unusual parameter patterns in extended stored procedure calls can help detect exploitation attempts before they succeed in causing system compromise or data exfiltration.