CVE-2010-3834 in MySQL
Summary
by MITRE
Unspecified vulnerability in 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 vectors related to "materializing a derived table that required a temporary table for grouping" and "user variable assignments."
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Analysis
by VulDB Data Team • 10/12/2021
This vulnerability affects multiple versions of the MySQL database management system, specifically targeting versions 5.0 before 5.0.92, 5.1 before 5.1.51, and 5.5 before 5.5.6. The issue manifests as a denial of service condition that can be triggered by authenticated remote attackers who exploit specific query execution paths involving derived table materialization and user variable assignments. The vulnerability stems from improper handling of temporary tables during query execution when grouping operations are required, creating a scenario where the server process becomes unstable and crashes. This represents a critical security flaw that could be exploited by malicious actors with valid database credentials to disrupt database services and potentially impact business operations.
The technical root cause of this vulnerability lies in the MySQL query optimizer's handling of derived tables that require temporary table creation for grouping operations. When user variables are assigned within queries that involve derived table materialization, the system fails to properly manage memory allocation and resource cleanup, leading to memory corruption or invalid memory access patterns. This flaw specifically occurs during the execution phase where MySQL attempts to materialize derived tables that require temporary storage for grouping operations, combined with user variable assignments that create additional complexity in the execution plan. The combination of these factors results in a condition where the server process becomes unstable and terminates unexpectedly, causing a denial of service. This vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of improper resource management in database query execution engines.
The operational impact of this vulnerability extends beyond simple service disruption, as it can potentially lead to complete database unavailability and data access interruptions for legitimate users. Attackers with authenticated access can craft specific SQL queries that trigger the crash condition, making this a particularly dangerous vulnerability in environments where database users have elevated privileges. The vulnerability affects both the performance and reliability of database systems, as server crashes can result in transaction rollbacks, connection drops, and potential data consistency issues. Organizations relying on MySQL for critical applications face significant risk from this vulnerability, particularly in production environments where database uptime is essential for business operations. The exploitability factor is relatively low since it requires authenticated access, but the impact can be severe, making it a priority for immediate remediation.
Mitigation strategies for this vulnerability primarily focus on applying the appropriate security patches released by Oracle for affected MySQL versions. Organizations should immediately upgrade to MySQL 5.0.92, 5.1.51, or 5.5.6, depending on their current version, to eliminate the risk of exploitation. Additionally, database administrators should implement monitoring solutions to detect unusual query patterns that might indicate exploitation attempts, particularly queries involving complex derived table operations with user variable assignments. Network segmentation and access controls can help limit the potential impact by restricting access to database systems, ensuring that only authorized users with legitimate business needs can establish connections. Security teams should also consider implementing database activity monitoring tools that can detect and alert on suspicious query execution patterns that might indicate attempts to trigger this vulnerability. The remediation process should include thorough testing of upgraded systems to ensure compatibility with existing applications and queries before full deployment. This vulnerability demonstrates the importance of maintaining up-to-date database software and implementing proper access controls to minimize the attack surface for authenticated users who might attempt to exploit known vulnerabilities.