CVE-2015-4756 in MySQL Server
Summary
by MITRE
Unspecified vulnerability in Oracle MySQL Server 5.6.22 and earlier allows remote authenticated users to affect availability via unknown vectors related to Server : InnoDB.
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Analysis
by VulDB Data Team • 06/03/2022
The vulnerability identified as CVE-2015-4756 represents a critical weakness within Oracle MySQL Server versions 5.6.22 and earlier, specifically affecting the InnoDB storage engine component. This issue falls under the category of availability disruption vulnerabilities, where authenticated remote attackers can potentially compromise system stability and service accessibility. The unspecified nature of the exact attack vectors makes this vulnerability particularly concerning for security professionals as it suggests multiple potential pathways for exploitation that may not be fully documented or understood. The InnoDB storage engine serves as the default storage engine for MySQL and handles transactional database operations, making any vulnerability in this component capable of significant operational impact.
The technical flaw manifests within the Server : InnoDB subsystem of MySQL, indicating that the vulnerability originates from the core database engine's handling of certain operations or data structures. InnoDB's role in managing transactions, row-level locking, and crash recovery makes it a prime target for attackers seeking to disrupt database availability. The vulnerability's classification as affecting availability rather than confidentiality or integrity suggests that attackers can cause denial of service conditions, potentially leading to database unavailability, system crashes, or performance degradation that impacts business operations and data access. This type of vulnerability aligns with CWE-119 which addresses weaknesses in memory management and data handling, particularly when dealing with buffer overflows or improper resource management in database engines.
From an operational standpoint, this vulnerability poses substantial risk to organizations relying on MySQL databases, especially those running versions prior to 5.6.22. The authenticated nature of the attack means that an attacker must first gain legitimate credentials to exploit the vulnerability, but this does not significantly reduce the threat level given that credential compromise can occur through various attack vectors including phishing, credential stuffing, or exploitation of other vulnerabilities. The impact extends beyond simple service disruption to potentially affect business continuity, data integrity, and customer access to services that depend on database availability. Organizations may experience downtime, data access delays, or complete system unavailability during exploitation attempts, leading to financial losses and reputational damage.
Security mitigations for CVE-2015-4756 primarily focus on immediate remediation through patching and updating to MySQL versions that address this vulnerability. Organizations should prioritize upgrading their MySQL installations to versions 5.6.23 or later where the vulnerability has been resolved. Network segmentation and access controls should be implemented to limit exposure of database systems to untrusted networks while maintaining necessary administrative access. Regular security assessments and monitoring of database systems for unusual activity patterns can help detect exploitation attempts. Additionally, implementing comprehensive backup and recovery procedures ensures that organizations can quickly restore services if exploitation occurs. The vulnerability's characteristics align with ATT&CK technique T1499 which covers resource hijacking and availability disruption through various means including database service interruption, making it essential for organizations to have incident response procedures in place for such scenarios.