CVE-2018-2816 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: Optimizer). Supported versions that are affected are 5.7.21 and prior. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.0 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 03/02/2023
The vulnerability identified as CVE-2018-2816 resides within the MySQL Server component, specifically within the Server: Optimizer subcomponent. This flaw affects MySQL versions 5.7.21 and earlier, representing a significant security concern for database administrators and system operators who rely on MySQL for critical data operations. The vulnerability's classification as easily exploitable indicates that attackers with high privileges and network access can leverage this weakness to compromise the targeted MySQL server instances. The CVSS 3.0 scoring system assigns a base score of 4.9, which reflects a medium severity level, though the availability impact assessment of "H" (high) underscores the potential for severe service disruption.
The technical nature of this vulnerability manifests within the query optimizer subsystem of MySQL, where an attacker with elevated privileges can craft specific database operations that trigger a condition leading to server instability. This flaw specifically enables an attacker to cause either a complete hang or a frequently repeatable crash of the MySQL server process, effectively resulting in a denial of service condition that can completely disrupt database operations. The attack vector requires network access and can be executed through multiple protocols, making it particularly dangerous in environments where database servers are accessible over networks. The requirement for high privileged access indicates that this vulnerability likely targets authenticated users who possess sufficient database permissions to execute problematic queries.
The operational impact of CVE-2018-2816 extends beyond simple service interruption, as it can potentially cause complete system unavailability for extended periods, requiring manual intervention for server recovery. This type of vulnerability directly contradicts the fundamental availability principles outlined in the CIA triad and can severely impact business continuity when database services become inaccessible. Organizations relying on MySQL for mission-critical applications face significant risk from this vulnerability, as database downtime can cascade into broader operational failures. The vulnerability's characteristics align with CWE-121, which addresses stack-based buffer overflow conditions, though the specific implementation appears to involve query processing rather than traditional memory corruption.
From a threat modeling perspective, this vulnerability maps to several ATT&CK techniques including T1499.004 for network denial of service and T1078 for legitimate credential use, as attackers must possess valid authentication credentials to exploit this weakness. The impact assessment reveals that while the vulnerability requires elevated privileges, it provides attackers with substantial control over database availability, making it attractive to malicious actors seeking to disrupt services. Security practitioners should note that this vulnerability represents a classic example of how optimizer flaws can lead to denial of service conditions, as these components are critical to database performance and stability. The vulnerability's presence in versions 5.7.21 and prior indicates that organizations should prioritize patch management efforts to ensure their MySQL installations are updated to versions that contain the necessary security fixes. The recommended mitigation strategy involves immediate deployment of Oracle's security patches or upgrading to MySQL versions that have addressed this specific optimizer-related instability issue, while maintaining robust monitoring to detect potential exploitation attempts.