CVE-2021-2036: 
MySQL vulnerability analysis and mitigation

CVE-2021-2036 is a vulnerability in the MySQL Server product of Oracle MySQL, specifically affecting the Server Optimizer component. The vulnerability affects MySQL versions 8.0.22 and prior. This vulnerability was disclosed on January 20, 2021, as part of Oracle's 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 high privileges with network access via multiple protocols to compromise MySQL Server (NVD).

A 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 (Ubuntu Security).

The vulnerability is considered easily exploitable but requires high privileges and network access via multiple protocols. An attacker needs to have high-privileged access to the system to exploit this vulnerability (NetApp Advisory).

The vulnerability has been fixed in MySQL version 8.0.23. Users are advised to upgrade to this version or later. For Ubuntu systems, fixed packages are available in version 8.0.23-1 for various distributions (Ubuntu Security).