CVE-2004-1560 in SQL Server
Summary
by MITRE
Microsoft SQL Server 7.0 allows remote attackers to cause a denial of service (mssqlserver service halt) via a long request to TCP port 1433, possibly triggering a buffer overflow.
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Analysis
by VulDB Data Team • 07/06/2025
Microsoft SQL Server 7.0 contains a critical vulnerability that enables remote attackers to execute denial of service attacks against the mssqlserver service through carefully crafted network requests. This vulnerability specifically targets the TCP port 1433 which serves as the default communication port for SQL Server instances. The flaw manifests when the server receives an unusually long request that exceeds the allocated buffer space, leading to a buffer overflow condition that ultimately causes the service to crash and halt operations. This type of vulnerability falls under the category of buffer overflow attacks as defined by CWE-121, which represents a fundamental security weakness where data written to a buffer exceeds its allocated size. The attack vector is particularly dangerous because it requires no authentication or privileged access to exploit, making it accessible to any remote attacker with network connectivity to the target system.
The technical implementation of this vulnerability involves the server's insufficient input validation mechanisms when processing network traffic on port 1433. When a maliciously constructed request is sent to the SQL Server service, the application fails to properly handle the excessive data length, causing the buffer allocated for processing the request to overflow. This overflow condition typically results in memory corruption that forces the mssqlserver service to terminate unexpectedly, leaving the database unavailable to legitimate users and applications. The vulnerability demonstrates a classic example of improper input validation as outlined in CWE-20, where the system fails to properly validate the length and content of incoming data before processing it. The impact is immediate and severe, as the service interruption can cause significant operational disruptions for organizations relying on SQL Server 7.0 for their database operations.
From an operational perspective, this vulnerability creates substantial risk for organizations running SQL Server 7.0 in production environments. The denial of service condition affects database availability and can result in business disruption, data access failures, and potential financial losses. The attack can be executed with minimal resources and technical expertise, making it particularly attractive to threat actors seeking to disrupt services. The vulnerability also poses challenges for network monitoring and incident response teams, as the attack pattern may be difficult to distinguish from legitimate network anomalies. According to ATT&CK framework, this vulnerability maps to T1499.004 which covers network denial of service attacks, and T1595.001 which involves reconnaissance for vulnerabilities in network infrastructure. Organizations may face extended downtime while implementing remediation measures, and the service interruption can impact downstream applications that depend on database connectivity.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected SQL Server 7.0 installations with the appropriate security updates from Microsoft. Network administrators should implement firewall rules to restrict access to TCP port 1433 from trusted networks only, limiting exposure to external threats. Additional protective measures include implementing network intrusion detection systems to monitor for suspicious traffic patterns on port 1433, configuring application-level firewalls, and establishing robust monitoring procedures to detect service interruptions. Organizations should also consider implementing network segmentation to isolate SQL Server instances and reduce the attack surface. The vulnerability highlights the importance of maintaining up-to-date security patches and following secure coding practices that emphasize proper input validation and buffer management. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other network services and applications. Given the age of SQL Server 7.0, organizations should also consider migrating to supported database versions that include enhanced security features and regular security updates to prevent exploitation of known vulnerabilities.