CVE-2021-2357: 
MySQL vulnerability analysis and mitigation

CVE-2021-2357 is a vulnerability in the MySQL Server product of Oracle MySQL, specifically affecting the Server: Optimizer component. The vulnerability affects versions 8.0.25 and prior. This vulnerability was disclosed in July 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 but requires high privileges and network access via multiple protocols to compromise MySQL Server (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 CPU).

The vulnerability requires a high-privileged attacker with network access via multiple protocols to exploit. It is considered easily exploitable once these conditions are met (NetApp Advisory).

Oracle has released patches for this vulnerability in MySQL version 8.0.26. Users are strongly recommended to update to this version or later. The fix has been incorporated into various distribution packages including Fedora's community-mysql-8.0.26 (Fedora Update).