CVE-2002-1376 in MySQL
Summary
by MITRE
libmysqlclient client library in MySQL 3.x to 3.23.54, and 4.x to 4.0.6, does not properly verify length fields for certain responses in the (1) read_rows or (2) read_one_row routines, which allows remote attackers to cause a denial of service and possibly execute arbitrary code.
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Analysis
by VulDB Data Team • 09/06/2025
The vulnerability described in CVE-2002-1376 represents a critical security flaw within the libmysqlclient client library component of MySQL database systems. This issue affects versions spanning from MySQL 3.x through 3.23.54 and 4.x through 4.0.6, making it a long-standing vulnerability that impacted a significant portion of the MySQL user base during its active period. The vulnerability stems from improper validation of length fields in specific data processing routines, creating a pathway for malicious actors to exploit the system through carefully crafted network responses.
The technical implementation of this vulnerability occurs within two primary routines: read_rows and read_one_row within the client library's data processing pipeline. These routines are responsible for parsing and handling data responses from MySQL servers, particularly when processing row-based data sets. The flaw manifests when the client library fails to properly validate the length fields contained within these responses, allowing attackers to craft malicious packets that contain malformed length indicators. This improper validation creates a condition where the client library attempts to process data based on incorrect length values, leading to buffer overflows or other memory corruption scenarios.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable remote code execution on affected systems. When attackers manipulate the length fields in database responses, they can cause the client library to allocate insufficient memory buffers or attempt to read beyond allocated memory boundaries. This memory corruption can result in application crashes and system instability, but more critically, it provides a potential vector for arbitrary code execution. Attackers who successfully exploit this vulnerability could gain control over the affected MySQL client processes, potentially allowing them to execute malicious code with the privileges of the MySQL client process.
From a cybersecurity perspective, this vulnerability aligns with CWE-129, which describes improper validation of length fields, and represents a classic example of a buffer overflow condition. The ATT&CK framework categorizes this type of vulnerability under the T1190 technique for exploitation of remote services, where attackers leverage memory corruption vulnerabilities to gain unauthorized access or execute malicious code. The attack surface is particularly concerning given that MySQL client libraries are widely deployed across various applications and systems, making the potential impact of this vulnerability substantial. The vulnerability demonstrates how seemingly minor flaws in data validation can create significant security risks, especially when these flaws occur in widely used client libraries that process untrusted network data.
Mitigation strategies for this vulnerability require immediate patching of affected MySQL installations to the latest available versions that contain the necessary security fixes. Organizations should also implement network segmentation and access controls to limit exposure of MySQL client systems to untrusted networks. Additionally, monitoring for suspicious network traffic patterns and implementing intrusion detection systems can help identify potential exploitation attempts. The vulnerability underscores the importance of maintaining up-to-date security patches and proper input validation in client applications that process network data, as these simple measures can prevent exploitation of similar memory corruption vulnerabilities.