CVE-2010-3838 in MySQL
Summary
by MITRE
MySQL 5.0 before 5.0.92, 5.1 before 5.1.51, and 5.5 before 5.5.6 allows remote authenticated users to cause a denial of service (server crash) via a query that uses the (1) GREATEST or (2) LEAST function with a mixed list of numeric and LONGBLOB arguments, which is not properly handled when the function s result is "processed using an intermediate temporary table."
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Analysis
by VulDB Data Team • 10/12/2021
The vulnerability described in CVE-2010-3838 represents a critical denial of service flaw affecting multiple versions of the MySQL database management system. This issue specifically impacts MySQL versions 5.0 prior to 5.0.92, 5.1 prior to 5.1.51, and 5.5 prior to 5.5.6, making it a widespread concern across several major release lines. The flaw stems from improper handling of data type mixing within the GREATEST and LEAST aggregate functions when processing queries that involve both numeric and LONGBLOB data types. This vulnerability is particularly dangerous because it can be exploited by authenticated remote attackers who do not require elevated privileges to cause significant system disruption.
The technical root cause of this vulnerability lies in how MySQL processes the intermediate temporary tables used during query execution when dealing with mixed data types in GREATEST and LEAST functions. When a query contains these functions with arguments that include both numeric values and LONGBLOB data types, the database engine fails to properly manage the memory allocation and data type conversion processes. This improper handling leads to memory corruption or invalid memory access conditions that ultimately result in the MySQL server process crashing. The issue is particularly insidious because it occurs during what should be a routine database operation, making it difficult to detect and prevent through normal security monitoring. The vulnerability is categorized under CWE-125 as an out-of-bounds read condition, which aligns with the memory corruption behavior observed during exploitation.
From an operational perspective, this vulnerability presents a significant risk to database availability and system stability. An authenticated attacker with access to the database can craft malicious queries that will cause the MySQL server to terminate unexpectedly, leading to service interruption for legitimate users. The impact extends beyond simple server crashes, as database administrators may experience extended downtime while investigating and recovering from the service disruption. This vulnerability particularly affects systems where database availability is critical, such as web applications, e-commerce platforms, and enterprise systems that rely heavily on MySQL for data operations. The fact that it requires only authenticated access makes it more accessible to internal threat actors or compromised user accounts, increasing the potential for both accidental and intentional exploitation.
The exploitation of this vulnerability aligns with several tactics outlined in the MITRE ATT&CK framework, specifically under the T1499 category for network denial of service attacks. Attackers can leverage this flaw to perform persistent disruption attacks against database services, potentially causing cascading failures in applications that depend on the affected database. Organizations should implement immediate patching strategies to address this vulnerability, as the affected versions are all considered outdated and unsupported. The recommended mitigation involves upgrading to MySQL versions 5.0.92, 5.1.51, or 5.5.6 respectively, which contain the necessary code modifications to properly handle mixed data type arguments in the GREATEST and LEAST functions. Additionally, database administrators should consider implementing query filtering mechanisms and monitoring for unusual patterns in GREATEST and LEAST function usage, particularly when mixed data types are involved, to detect potential exploitation attempts.