CVE-2003-0353 in Data Access Components
Summary
by MITRE
Buffer overflow in a component of SQL-DMO for Microsoft Data Access Components (MDAC) 2.5 through 2.7 allows remote attackers to execute arbitrary code via a long response to a broadcast request to UDP port 1434.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 08/17/2025
The vulnerability described in CVE-2003-0353 represents a critical buffer overflow flaw within Microsoft Data Access Components MDAC versions 2.5 through 2.7 specifically affecting SQL-DMO functionality. This vulnerability exists in the handling of network responses to broadcast requests sent to UDP port 1434, which is the default port used by Microsoft SQL Server for instance discovery and broadcasting services. The flaw arises when the SQL-DMO component processes incoming responses from SQL Server instances, failing to properly validate the length of data received in broadcast messages. This insufficient input validation creates a condition where malicious actors can craft specially formatted responses exceeding the allocated buffer space, leading to memory corruption and potential code execution.
The technical nature of this vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The attack vector leverages the UDP protocol's connectionless nature, making it particularly dangerous as attackers can exploit this without establishing a proper connection or authentication. The vulnerability specifically targets the SQL-DMO component's handling of broadcast responses, which are typically used for discovering available SQL Server instances on a network. When a malformed response containing excessive data is received, the buffer overflow can overwrite critical memory segments including return addresses, potentially allowing remote code execution with the privileges of the affected system process.
The operational impact of this vulnerability extends beyond simple exploitation as it enables attackers to gain unauthorized access to systems running vulnerable MDAC versions. The remote execution capability means that attackers can perform actions such as installing malicious software, modifying or deleting data, creating new user accounts, or establishing persistent access to the compromised systems. This vulnerability particularly affects enterprise environments where SQL Server instances are commonly deployed and where network discovery protocols are actively used. The fact that the attack occurs through UDP port 1434 makes it especially concerning as this port is often left open and accessible across network boundaries, providing attackers with multiple potential entry points. Organizations with multiple SQL Server instances may be particularly vulnerable as the broadcast mechanism can cause cascading effects throughout network infrastructure.
Mitigation strategies for CVE-2003-0353 should focus on immediate patching of affected MDAC versions, as Microsoft released security updates specifically addressing this vulnerability. Network segmentation and firewall rules should be implemented to restrict access to UDP port 1434, particularly from untrusted networks and systems. The implementation of network monitoring solutions can help detect unusual broadcast traffic patterns that may indicate exploitation attempts. Additionally, organizations should consider disabling SQL Server instance discovery features when not actively needed, as this reduces the attack surface. From an ATT&CK framework perspective, this vulnerability maps to techniques involving remote code execution and privilege escalation, with the attack chain typically following T1190 for exploitation of remote services and T1059 for execution of malicious code. Regular security assessments and network scanning should be conducted to identify systems running vulnerable MDAC versions, and system administrators should implement comprehensive patch management processes to ensure timely deployment of security updates across all network infrastructure.