A critical vulnerability, identified as CVE-2023-21955, has been discovered in the MySQL Server product of Oracle MySQL. The vulnerable component of the software is Server: Partition. Versions 8..32 and prior have been found to be affected by this vulnerability. The exploit allows a high privileged attacker with network access via multiple protocols to compromise the MySQL Server. A successful attack using this vulnerability can result in an unauthorized ability to cause a hang or frequently repeatable crash (complete DoS) of the MySQL Server. The CVSS 3.1 Base Score for this vulnerability is 4.9, with a focus on availability impacts. The CVSS Vector is (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).

Exploit Details

The vulnerability found in MySQL Server's partition component can be easily exploited by a high privileged attacker having network access via multiple protocols. This exploit, once executed, can lead to a complete DoS attack, compromising the server's availability.

Code Snippet

While the exact code for exploiting this vulnerability cannot be shared for security purposes, below is a generic example of how an attacker might take advantage of this vulnerability:

// Attacker code to exploit CVE-2023-21955
function exploitMySQLPartitionVulnerability(host, port, credentials) {
  // Connect to the server using the provided host, port and credentials
  let mysqlConnection = establishMySQLConnection(host, port, credentials);

  // Craft a malicious query that takes advantage of the partition vulnerability
  let maliciousQuery = createMaliciousPartitionQuery();

  // Execute the malicious query

  // Close the connection

1. Oracle Critical Patch Update Advisory - January 2023: This link contains the original announcement from Oracle regarding this vulnerability and how it affects the MySQL Server product.

2. MySQL Server: Partition Vulnerability (CVE-2023-21955): This link provides more detailed information on the vulnerability, including how it was discovered and reported.

3. Common Vulnerability Scoring System Calculator: This link will redirect you to a page where you can calculate the CVSS score for this vulnerability using the provided vector.

Update to the latest version of MySQL Server (8..33 or later) if possible.

- Apply the appropriate patch for your specific version: Oracle provides patches for its MySQL Server versions 8..32 and prior. Check the Oracle Critical Patch Update Advisory - January 2023 for more details.


The MySQL Server vulnerability CVE-2023-21955 poses a significant threat to the availability of affected systems. It is crucial to apply the recommended patches and follow security best practices to mitigate the risks associated with this exploit. By staying vigilant against such vulnerabilities, you can protect your systems and ensure the security of your MySQL Server deployments.


Published on: 04/18/2023 20:15:00 UTC
Last modified on: 04/27/2023 15:15:00 UTC