CVE-2020-14837: 
MySQL vulnerability analysis and mitigation

CVE-2020-14837 is a vulnerability in the MySQL Server product of Oracle MySQL, specifically affecting the Server Optimizer component. The vulnerability affects MySQL Server versions 8.0.21 and prior. This vulnerability was disclosed in Oracle's October 2020 Critical Patch Update (Oracle CPU).

The vulnerability has been assigned a CVSS 3.1 Base Score of 4.9 (Medium severity) with the following vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H. The vulnerability is easily exploitable and requires a high-privileged attacker with network access via multiple protocols to compromise MySQL Server (Oracle CPU, NetApp Advisory).

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. The vulnerability only affects availability, with no direct impact on confidentiality or integrity (Oracle CPU, NetApp Advisory).

The vulnerability is considered easily exploitable but requires a high-privileged attacker with network access via multiple protocols. The attack requires high privileges but no user interaction to exploit (Oracle CPU).

Oracle has released patches to address this vulnerability in their October 2020 Critical Patch Update. Users should upgrade to MySQL version 8.0.22 or later to mitigate this vulnerability. For Ubuntu systems, the fix is available in version 8.0.22-0ubuntu0.20.04.2 (Ubuntu Security, Gentoo Security).