CVE-2018-3187 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: Optimizer). Supported versions that are affected are 5.7.23 and prior and 8.0.12 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 as well as unauthorized update, insert or delete access to some of MySQL Server accessible data. CVSS 3.0 Base Score 5.5 (Integrity and Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H).
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Analysis
by VulDB Data Team • 05/29/2023
The vulnerability identified as CVE-2018-3187 resides within the MySQL Server optimizer component, specifically affecting Oracle MySQL versions 5.7.23 and earlier, as well as 8.0.12 and earlier. This flaw represents a critical security weakness that enables attackers with high privileges and network access to compromise the integrity and availability of MySQL Server operations. The vulnerability's classification as easily exploitable indicates that attackers with minimal technical sophistication can leverage this weakness to gain unauthorized access to sensitive database operations. The CVSS 3.0 score of 5.5 reflects the balanced impact across integrity and availability aspects, with a base score that places this vulnerability in the medium severity category. The attack vector requires network access via multiple protocols, suggesting that the vulnerability can be exploited from various connection methods that MySQL supports.
The technical implementation of this vulnerability stems from improper handling within the optimizer module, which is responsible for determining the most efficient execution plan for database queries. When an attacker crafts specific malicious queries or conditions that trigger the flawed optimizer logic, the system can experience either complete denial of service through hanging or repeated crashes that effectively render the database unavailable. This behavior aligns with CWE-121, which describes heap-based buffer overflow conditions, and demonstrates how optimization routines can introduce security weaknesses when proper input validation and boundary checking are insufficient. The vulnerability's impact extends beyond simple service disruption as it also enables unauthorized modification of database content, allowing attackers to perform unauthorized updates, inserts, or deletes on sensitive data within the MySQL Server environment.
The operational implications of CVE-2018-3187 are particularly concerning for organizations relying on MySQL for critical data operations, as the vulnerability can be exploited to cause complete database service outages while simultaneously enabling data corruption or manipulation. The requirement for high privileged access suggests that this vulnerability is most likely to be exploited by insiders or attackers who have already gained elevated database credentials, though the network accessibility means that external attackers with proper credentials could also leverage this weakness. The availability impact is particularly severe as the vulnerability can cause complete system hangs or repeated crashes that require manual intervention to restore normal database operations. Organizations implementing this vulnerability in their security posture should consider the ATT&CK technique T1489 which covers disruption of services through the use of system binaries, as this vulnerability could be exploited to achieve similar outcomes through database service disruption.
Mitigation strategies for CVE-2018-3187 should prioritize immediate patching of affected MySQL Server versions to the latest available releases that contain fixes for the optimizer module vulnerability. Organizations should also implement network segmentation and access controls to limit the attack surface, ensuring that only authorized personnel have high privileged access to database systems. The principle of least privilege should be enforced across all database user accounts, with strict monitoring of database activities for anomalous query patterns that could indicate exploitation attempts. Additionally, implementing database activity monitoring solutions can help detect unauthorized modifications or attempts to trigger the vulnerable optimizer logic. Regular security assessments and vulnerability scanning should include checks for this specific vulnerability to ensure that all MySQL installations are properly updated and patched according to Oracle's security advisories. The remediation process should also include comprehensive testing of patched systems to verify that the fix does not introduce compatibility issues with existing database applications and workflows.