CVE-2020-14809: 
MySQL vulnerability analysis and mitigation

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer) affects versions 8.0.21 and prior. This vulnerability was disclosed in October 2020 and is tracked as CVE-2020-14809. The vulnerability exists in the MySQL Server's Optimizer component (Oracle Advisory).

The vulnerability has been assigned a CVSS 3.1 Base Score of 4.9 (Medium) 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 requires high privileges and network access via multiple protocols to exploit. The attack complexity is considered low, and no user interaction is required (NVD).

Successful exploitation of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. The vulnerability only affects availability with no impact on confidentiality or integrity (Oracle Advisory, NetApp Advisory).

Oracle has released patches to address this vulnerability in MySQL version 8.0.22. Ubuntu has also released fixed versions: 8.0.22-0ubuntu0.20.10.2 for Ubuntu 20.10 and 8.0.22-0ubuntu0.20.04.2 for Ubuntu 20.04 LTS. Users are strongly advised to upgrade to these patched versions (Ubuntu Notice).