CVE-2015-4761 in MySQL Server
Summary
by MITRE
Unspecified vulnerability in Oracle MySQL Server 5.6.24 and earlier allows remote authenticated users to affect availability via unknown vectors related to Server : Memcached.
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Analysis
by VulDB Data Team • 06/03/2022
The vulnerability identified as CVE-2015-4761 represents a significant security flaw within Oracle MySQL Server versions 5.6.24 and earlier, specifically impacting the server's interaction with Memcached components. This issue manifests as an availability threat that can be exploited by remote authenticated users, indicating that attackers must possess valid credentials to leverage this vulnerability. The unspecified nature of the exact attack vectors suggests that the flaw resides in the complex integration between MySQL's server functionality and Memcached caching mechanisms, creating potential points of failure that could disrupt system operations.
The technical implementation of this vulnerability stems from the way MySQL Server handles communication with Memcached plugins or integrated caching features. When authenticated users interact with the MySQL server that has Memcached integration enabled, certain operations can trigger unexpected behavior in the memory management systems. This typically involves memory allocation patterns or resource handling that becomes unstable under specific conditions. The vulnerability operates at the intersection of database server operations and distributed caching systems, where improper handling of memory resources can lead to denial of service conditions. The attack surface expands when considering that Memcached is often used to accelerate database queries, making this a particularly dangerous issue for high-traffic applications.
From an operational impact perspective, this vulnerability creates substantial risks for database availability and system reliability. Remote authenticated attackers can potentially cause service disruption by triggering memory exhaustion or resource corruption within the MySQL server process. The availability impact means that legitimate users may experience database downtime or performance degradation, which can cascade into broader business continuity issues. Organizations relying on MySQL with Memcached integration face potential financial losses due to service interruptions, increased administrative overhead for monitoring and recovery, and possible data access delays. The threat is particularly concerning because it requires only authenticated access, meaning that insiders or compromised accounts could exploit this vulnerability to cause service disruption.
The vulnerability aligns with CWE-400, which addresses "Uncontrolled Resource Consumption" and specifically relates to memory management issues that can lead to denial of service conditions. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique for "Network Denial of Service" and potentially T1566.001 for "Phishing" if the authentication credentials are obtained through social engineering. Organizations should implement immediate mitigations including upgrading to MySQL versions that address this vulnerability, disabling Memcached integration if not essential, and implementing network segmentation to limit access to database servers. Regular security assessments should include verification of all database plugin configurations and monitoring for unusual memory consumption patterns. Additionally, access controls should be strictly enforced to minimize the attack surface, and comprehensive logging should be implemented to detect potential exploitation attempts. The remediation process requires careful planning to ensure that database functionality remains intact while addressing the availability threat posed by this vulnerability.