CVE-2012-2749 in MySQL Server
Summary
by MITRE
MySQL 5.1.x before 5.1.63 and 5.5.x before 5.5.24 allows remote authenticated users to cause a denial of service (mysqld crash) via vectors related to incorrect calculation and a sort order index.
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Analysis
by VulDB Data Team • 03/27/2021
The vulnerability identified as CVE-2012-2749 represents a critical denial of service flaw affecting MySQL database systems across multiple version lines. This issue specifically impacts MySQL 5.1.x versions prior to 5.1.63 and 5.5.x versions prior to 5.5.24, creating a significant risk for database administrators and security practitioners managing these systems. The vulnerability stems from improper handling of sort order calculations within the database engine, which can be exploited by authenticated remote attackers to crash the mysqld process and effectively render the database service unavailable to legitimate users. The flaw operates through a specific class of database operations that involve incorrect calculation of sort order indexes, leading to memory corruption and subsequent process termination.
This vulnerability falls under the CWE-121 category of stack-based buffer overflow, though it manifests more accurately as a heap-based memory corruption issue within the MySQL query execution engine. The technical implementation involves the database engine's handling of complex sorting operations where it fails to properly validate or calculate sort order indexes during query processing. When an authenticated user submits a specially crafted query that triggers the problematic code path, the system encounters an arithmetic overflow or underflow condition in the index calculation logic, resulting in corrupted memory structures that cause the mysqld process to crash. The vulnerability is particularly dangerous because it requires only authentication to the database system, making it accessible to any user with valid credentials rather than requiring privileged access or exploitation of additional vulnerabilities.
The operational impact of CVE-2012-2749 extends beyond simple service disruption, as it can lead to complete database unavailability and potential data integrity concerns during the recovery process. Organizations relying on MySQL for critical business operations face significant risk of service interruption, which could result in financial losses, compliance violations, and reputational damage. The vulnerability affects systems where database queries involve complex sorting operations, particularly when dealing with large datasets or multiple join operations that require extensive sorting and indexing calculations. Attackers can exploit this weakness systematically by crafting queries that force the database engine into the vulnerable code path, potentially leading to repeated service disruptions if not properly addressed. The crash behavior is typically immediate and deterministic, making it difficult to implement effective workarounds without patching the underlying software.
Mitigation strategies for CVE-2012-2749 primarily focus on applying the vendor-provided patches and updates that address the specific memory handling and sort order calculation issues within the MySQL engine. Organizations should prioritize upgrading to MySQL 5.1.63 or later versions for the 5.1.x branch, and MySQL 5.5.24 or later for the 5.5.x branch to eliminate the vulnerability. Additionally, implementing network segmentation and access controls can help limit the attack surface by restricting access to database systems and requiring strong authentication mechanisms. Database administrators should also consider implementing monitoring and alerting systems that can detect unusual patterns of database crashes or service interruptions, which may indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1499.004 for network denial of service, and represents a classic example of how seemingly minor code flaws in database engines can create significant operational risks. Regular security assessments and vulnerability scanning should include checks for this specific vulnerability to ensure comprehensive protection against potential exploitation attempts.