CVE-2020-14540: 
MySQL vulnerability analysis and mitigation

CVE-2020-14540 is a vulnerability discovered in Oracle MySQL Server's DML (Data Manipulation Language) component. The vulnerability affects MySQL Server versions 5.7.30 and prior, and 8.0.20 and prior. It was disclosed in July 2020 as part of Oracle's Critical Patch Update (Oracle CPU).

This is a medium severity vulnerability with a CVSS v3.1 Base Score of 4.9, and vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H. The vulnerability requires a high-privileged attacker with network access via multiple protocols to exploit (NVD).

Successful exploitation of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash, leading to a complete Denial of Service (DoS) of MySQL Server (Oracle CPU, NetApp Advisory).

The vulnerability is considered easily exploitable but requires high privileges and network access. The attack complexity is rated as low, indicating that specialized access conditions or extenuating circumstances do not need to exist for exploitation (NVD).

Oracle released patches for affected versions in the July 2020 Critical Patch Update. Ubuntu users can update to mysql-server-8.0 version 8.0.21-0ubuntu0.20.04.3 for Ubuntu 20.04, and mysql-server-5.7 version 5.7.31-0ubuntu0.18.04.1 for Ubuntu 18.04 (Ubuntu Notice). Fedora users can update to community-mysql version 8.0.21-11 (Fedora Update).