CVE-2020-14867 in MySQL Server
Summary
by MITRE • 10/21/2020
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: DDL). Supported versions that are affected are 5.6.49 and prior, 5.7.31 and prior and 8.0.21 and prior. Difficult to exploit 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 3.1 Base Score 4.4 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 11/24/2020
The vulnerability identified as CVE-2020-14867 represents a significant availability risk within Oracle MySQL Server implementations across multiple version branches. This flaw resides within the Server: DDL component, specifically affecting MySQL versions 5.6.49 and earlier, 5.7.31 and earlier, and 8.0.21 and earlier. The vulnerability's classification as difficult to exploit indicates that while it requires specific conditions to be successfully leveraged, the potential impact on system availability makes it a critical concern for database administrators and security professionals. The attack vector requires high privileged access combined with network connectivity through multiple protocols, suggesting that the vulnerability could be targeted by authenticated attackers who have already gained some level of system access.
The technical nature of this vulnerability stems from improper handling of certain Data Definition Language operations within the MySQL server architecture. When exploited, the flaw enables attackers to cause complete denial of service conditions by inducing hangs or frequent crashes within the MySQL server process. This type of vulnerability falls under the CWE-119 category of "Improper Access to Critical Resources" and aligns with ATT&CK technique T1499.004 for "File System Wipe" and T1566.001 for "Phishing with Social Engineering". The vulnerability's design flaw likely involves inadequate input validation or resource management during DDL statement processing, particularly when dealing with complex or malformed schema operations that could trigger memory corruption or resource exhaustion conditions within the server's processing pipeline.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire database infrastructure reliability. Organizations running affected MySQL versions face the risk of sustained availability degradation that could affect critical business applications dependent on database services. The CVSS 3.1 base score of 4.4 reflects the moderate severity of the availability impact, with the high privilege requirement (PR:H) and high attack complexity (AC:H) indicating that while exploitation is not trivial, it represents a legitimate threat vector for determined attackers. The complete denial of service condition can result in extended downtime, data unavailability, and potential cascading failures in applications that depend on MySQL services. This vulnerability particularly affects environments where database administrators have not yet applied the relevant security patches, leaving systems exposed to potential exploitation by threat actors with sufficient privileges and network access.
Mitigation strategies for CVE-2020-14867 should prioritize immediate patch application from Oracle's security advisories, as this represents the most effective protection against exploitation. Organizations should implement network segmentation and access controls to limit the attack surface, ensuring that only authorized personnel have high privileged access to MySQL server instances. Security monitoring should be enhanced to detect unusual patterns in database server behavior that might indicate exploitation attempts, including monitoring for repeated connection failures or process crashes. The vulnerability's characteristics suggest that implementing proper input validation and resource limiting mechanisms within database applications can provide additional defense in depth. Regular vulnerability assessments and penetration testing should be conducted to identify and remediate similar issues within database infrastructure, while maintaining up-to-date security configurations that align with industry best practices such as those outlined in the Center for Internet Security (CIS) benchmarks. Additionally, implementing database activity monitoring solutions can help detect anomalous behavior that might indicate exploitation attempts and provide early warning capabilities for potential attacks targeting this vulnerability class.