CVE-2004-2149 in MySQL
Summary
by MITRE
Buffer overflow in the prepared statements API in libmysqlclient for MySQL 4.1.3 beta and 4.1.4 allows remote attackers to cause a denial of service via a large number of placeholders.
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Analysis
by VulDB Data Team • 07/06/2025
The vulnerability described in CVE-2004-2149 represents a critical buffer overflow condition within the prepared statements application programming interface of libmysqlclient library used in MySQL database systems. This flaw affects specifically MySQL versions 4.1.3 beta and 4.1.4, where the implementation fails to properly validate the number of placeholders within prepared statements. The buffer overflow occurs when remote attackers submit maliciously crafted SQL queries containing an excessive number of placeholders, causing the application to write beyond allocated memory boundaries. This fundamental memory management issue stems from inadequate input validation and boundary checking within the prepared statement processing logic.
The technical exploitation of this vulnerability leverages the inherent design flaw in how the libmysqlclient library handles placeholder expansion during prepared statement execution. When a prepared statement contains an excessive number of placeholders, the system's internal buffer allocation mechanisms fail to accommodate the resulting data structure, leading to memory corruption. The vulnerability is classified as a classic buffer overflow according to CWE-121, which specifically addresses stack-based buffer overflow conditions. This type of flaw allows attackers to manipulate memory contents and potentially execute arbitrary code, though in this specific case the impact is limited to denial of service rather than arbitrary code execution.
From an operational perspective, this vulnerability presents significant risks to database availability and system stability. Remote attackers can exploit this condition to crash database server processes, effectively causing a denial of service that disrupts legitimate database operations and can result in extended downtime. The attack vector is particularly concerning as it requires no authentication credentials, making it accessible to anyone with network access to the affected MySQL server. The vulnerability affects the core database connectivity layer, meaning that any application relying on MySQL prepared statements for database operations becomes vulnerable to this attack, potentially compromising entire application ecosystems that depend on database availability.
The mitigation strategies for this vulnerability should include immediate patching of affected MySQL installations to versions that address the buffer overflow condition in libmysqlclient. Organizations should implement network segmentation and access controls to limit exposure of MySQL servers to untrusted networks, following principles outlined in the MITRE ATT&CK framework for database security. Additionally, monitoring systems should be configured to detect unusual patterns of prepared statement usage that might indicate exploitation attempts. Security teams should also consider implementing input validation controls and rate limiting mechanisms for database connections to reduce the effectiveness of potential attacks. The vulnerability highlights the importance of proper memory management in database client libraries and underscores the necessity of thorough testing of edge cases in prepared statement processing to prevent similar issues in future implementations.