CVE-2023-21840 - Easily Exploitable MySQL Server Vulnerability Impacting 5.7.40 and Prior Versions

A new vulnerability, labeled CVE-2023-21840, has been discovered within the MySQL Server product of Oracle MySQL, specifically targeting the Server: PS component. Supported versions affected by this vulnerability include 5.7.40 and prior versions. This easily exploitable vulnerability allows a high-privileged attacker with network access via multiple protocols to compromise the MySQL Server. Successful attacks can result in unauthorized ability to cause a hang or frequently repeatable crashes (complete Denial of Service or DOS) of MySQL Server. The CVSS 3.1 Base Score of this vulnerability is 4.9, which corresponds to 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).

Here's a basic illustration of this vulnerability

# Python Code Example Demonstrating Exploitable MySQL Connection
import pymysql

# Creating a connection to the MySQL server
connection = pymysql.connect(host='<mysql_server>',
                             user='<high_privileged_user>',
                             password='<user_password>',
                             db='<database>')

# Exploiting the MySQL Server's vulnerability
exploit = "<exploit_code_here>"

with connection.cursor() as cursor:
    cursor.execute(exploit)

Exploit Details

To better understand the severity and repercussions of this vulnerability, here are the exploit details:

1. Successful attacks can result in a complete denial of service (DOS) of MySQL Server: If an attacker is able to exploit this vulnerability, they can potentially cause the Server to either hang or crash repeatedly. This will impact the availability of any service or application reliant on the MySQL Server.

2. Attackers require network access via multiple protocols: A high-privileged attacker with access to the network can exploit this vulnerability. The attacker can use multiple protocols, increasing the flexibility and potential attack methods.

3. Affects supported versions 5.7.40 and prior: The vulnerability impacts a wide range of MySQL Server versions, specifically those versions that are supported by Oracle MySQL, including version 5.7.40 and all prior versions.

For more information and resources on CVE-2023-21840, consult the following references

- Oracle Security Alert Advisory - CVE-2023-21840: (https://www.oracle.com/security-alerts/advisory/CVE-2023-21840.html)
- NVD - CVE-2023-21840 Detail: (https://nvd.nist.gov/vuln/detail/CVE-2023-21840)

Conclusion

Organizations using MySQL Server (versions 5.7.40 and prior) are highly recommended to apply the necessary patches and updates provided by the vendor (Oracle) to mitigate the risks associated with this vulnerability. Additionally, monitor for any suspicious network activity that may signal an attacker attempting to exploit the vulnerability. By taking these steps, organizations can significantly reduce the risks associated with CVE-2023-21840 and ensure greater protection for their MySQL environments.

Timeline

Published on: 01/18/2023 00:15:00 UTC
Last modified on: 01/24/2023 19:25:00 UTC