The Common Vulnerabilities and Exposures (CVE) system is the industry-standard to report and document cybersecurity vulnerabilities. The CVE-2023-22111 refers to a specific vulnerability in the MySQL Server product of Oracle MySQL which affects versions 8..33 and prior. This vulnerability is related to the Server: User-Defined Functions (UDF) component and could lead to a successful denial of service (DOS) attack on MySQL Server. In this long-read post, we will explore the details of this vulnerability, discuss the exploit, and share links to original references. So, let's dive in.

Vulnerability Details

CVE-2023-22111 impacts the MySQL Server product, specifically in the Server: UDF component. The affected versions are 8..33 and prior, and the vulnerability can be exploited by a high privileged attacker who has network access via multiple protocols. The exploit can result in causing a hang or frequently repeatable crash (complete DOS) of MySQL Server. The CVSS (Common Vulnerability Scoring System) 3.1 Base Score for this vulnerability is 4.9, with the main impact being on availability.

The CVSS Vector for this vulnerability is: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H)

Exploit Details

A high privileged attacker can exploit this vulnerability by utilizing the MySQL UDF functionality. UDF allows users to define their custom functions in MySQL, extending the capabilities of the SQL queries. An attacker with access to the UDF can craft a malicious UDF that triggers the vulnerability and causes MySQL Server to crash, resulting in a denial of service attack.

Here's a simple code snippet that illustrates the use of UDF in MySQL

-- Create a simple UDF that adds two numbers
CREATE FUNCTION my_add
  RETURNS INTEGER
  LANGUAGE SQL
  DETERMINISTIC
  NO SQL
  SQL SECURITY INVOKER
  BEGIN
    RETURN arg1 + arg2;
  END;
 
-- Use the UDF in a SELECT query
SELECT my_add(5, 3);

Please note that this code snippet is for illustration purposes and does not contain the exploit code. The actual exploit code would be crafted by an attacker to specifically target the vulnerability and cause the DOS attack.

Original References

To learn more about the CVE-2023-22111 vulnerability and obtain additional technical information, please visit the following links:

1. Oracle Critical Patch Update Advisory - April 2023 - This Oracle advisory provides a high-level overview of the vulnerabilities addressed in their product line, including the MySQL Server vulnerability discussed here.

2. National Vulnerability Database (NVD) - CVE-2023-22111 - The NVD entry for this vulnerability provides a detailed CVSS score breakdown and further information about the affected components and products.

3. MySQL User-Defined Function (UDF) Documentation - MySQL's official documentation offers a comprehensive guide on how to create and manage user-defined functions in MySQL, which will help you better understand the context of this vulnerability.

Conclusion

CVE-2023-22111 is a significant vulnerability that could lead to a denial of service attack on affected MySQL Servers. It is crucial for organizations using MySQL Server 8..33 and prior to stay up-to-date with security patches and harden their systems against such attacks. We recommend reviewing the original references for further information and timely patching of your MySQL systems. Stay safe and keep your guard up!

Timeline

Published on: 10/17/2023 22:15:15 UTC
Last modified on: 10/27/2023 15:15:12 UTC