CVE-2002-0729 in SQL Server
Summary
by MITRE
Microsoft SQL Server 2000 allows remote attackers to cause a denial of service via a malformed 0x08 packet that is missing a colon separator.
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Analysis
by VulDB Data Team • 05/09/2019
Microsoft SQL Server 2000 contains a critical vulnerability that enables remote attackers to execute denial of service attacks through the manipulation of network packet structures. This flaw specifically targets the protocol handling mechanism within the SQL Server network layer where the system expects a particular format for incoming packets. The vulnerability manifests when a maliciously crafted 0x08 packet is transmitted without the required colon separator character, causing the server to crash or become unresponsive. This type of vulnerability falls under the category of improper input validation and can be classified as CWE-129, which represents an insufficient validation of the length of a field. The attack vector operates over the network protocol used by SQL Server, making it accessible to remote threat actors without requiring local system access or authentication credentials. The impact extends beyond simple service disruption as the denial of service condition can render the entire database server inaccessible to legitimate users and applications that depend on its availability.
The technical implementation of this vulnerability demonstrates a fundamental flaw in the protocol parsing logic within SQL Server 2000's network communication stack. When the server receives a packet with identifier 0x08, it expects a specific formatting structure that includes a colon separator as part of the packet's data payload. The absence of this expected character causes the parsing routine to fail, leading to an unhandled exception that terminates the service or forces it into a non-responsive state. This behavior aligns with ATT&CK technique T1499.004, which involves network denial of service attacks targeting applications and services. The vulnerability is particularly concerning because it operates at the protocol level, meaning that even legitimate network traffic could be disrupted if attackers can successfully exploit this weakness. The flaw represents a classic example of a buffer over-read or improper input handling scenario where the system fails to properly validate the structure of incoming data before processing it.
The operational impact of this vulnerability extends significantly beyond immediate service disruption, potentially affecting business continuity and data availability for organizations relying on SQL Server 2000 infrastructure. When exploited, the denial of service condition can prevent legitimate database connections, causing cascading failures throughout applications and services that depend on database connectivity. The vulnerability affects systems where SQL Server 2000 is deployed in production environments, particularly in scenarios where network access is not properly restricted or where firewalls are not adequately configured to filter malformed packets. Organizations with limited network segmentation or those operating legacy systems without proper security controls are especially vulnerable to exploitation. The attack requires minimal technical expertise to execute, making it a particularly attractive vector for threat actors seeking to disrupt database services. This vulnerability also demonstrates the importance of proper protocol validation and input sanitization in network services, as the flaw allows attackers to cause service disruption through simple packet manipulation rather than requiring complex exploitation techniques.
Mitigation strategies for this vulnerability should focus on both immediate protective measures and long-term architectural improvements. Network-level protections including firewall rules that filter malformed packets and intrusion detection systems capable of identifying suspicious 0x08 packet patterns can provide immediate defense against exploitation attempts. Organizations should implement proper network segmentation to limit access to SQL Server instances and ensure that only authorized systems can communicate with database services. The most effective long-term solution involves upgrading to supported versions of SQL Server that include proper input validation and protocol handling improvements. Security patches and service packs released by Microsoft specifically address this vulnerability by implementing stricter packet validation routines and proper error handling for malformed input. Additionally, implementing network monitoring and logging capabilities can help detect exploitation attempts and provide early warning of potential attacks. Organizations should also consider implementing redundant database systems and failover mechanisms to maintain service availability during potential exploitation events, aligning with security best practices outlined in industry standards such as NIST SP 800-53 and ISO 27001 frameworks that emphasize the importance of robust input validation and secure protocol implementation.