CVE-2023-21962: Understanding the Vulnerability in Oracle MySQL Server Component Services and How to Prevent DOS Attacks

Recently, a vulnerability has been discovered in the MySQL server product, specifically in Oracle MySQL's component services (CVE-2023-21962). This vulnerability affects supported versions up to 8..32 and can be exploited by a highly privileged attacker, allowing them to cause a hang or frequently repeatable crash (complete DOS) in the MySQL server. The CVSS 3.1 Base Score for this vulnerability is 4.9, with the CVSS Vector being (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H). In this post, we will discuss the details of this vulnerability, some code snippets to illustrate the problem, and links to original references for more information.

Vulnerability Details

The vulnerability (CVE-2023-21962) resides in the MySQL Server product of Oracle MySQL, particularly in the server component services. Versions 8..32 and prior are affected by this vulnerability, and it allows a high privileged attacker to compromise the MySQL server with ease. With successful exploitation, an attacker can gain unauthorized ability to cause a hang or a frequently repeatable crash in the MySQL server, resulting in a complete denial of service (DOS) attack. The risk posed by this vulnerability is significant, as it impacts the availability of the MySQL server.

The vulnerability can be exploited through multiple network protocols, making the attack surface larger and more accessible to potential attackers. The CVSS 3.1 Base Score is 4.9, indicating a medium severity issue. The CVSS Vector (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H) demonstrates that the vulnerability can be exploited over a network (AV:N), has a low attack complexity (AC:L), requires high privileges (PR:H), does not require user interaction (UI:N), and affects only the availability of the server (A:H).

Exploit Details

In order to exploit this vulnerability, an attacker must have high privileges on the targeted system. While the specific code for exploiting the vulnerability is not provided, a code snippet can illustrate how an attacker might attempt to compromise the system:

import socket

target_IP = '192.168.1.10' # Victim's MySQL server IP address
target_port = 3306 # MySQL server's default port

# Craft a malicious packet to send to the MySQL server
malicious_packet = "your_malicious_payload_here"

# Create a socket object and connect to the target IP and port
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((target_IP, target_port))

# Send the malicious packet to the server
s.send(malicious_packet)

# Close the socket connection
s.close()

It is important to note that the above code is an illustration of how an attacker might go about exploiting the vulnerability. It is not intended to be used for malicious purposes and should be treated as educational content.

For more information on this vulnerability, the following links provide useful resources

- Oracle Critical Patch Update Advisory - October 2022: https://www.oracle.com/security-alerts/cpuoct2022.html
- NVD - CVE-2023-21962: https://nvd.nist.gov/vuln/detail/CVE-2023-21962

Conclusion

CVE-2023-21962 is a significant vulnerability in Oracle MySQL Server's component services. By understanding how the vulnerability works and what it affects, it is possible to take steps to minimize the risk and protect your systems. Ensuring that your MySQL server is updated to a version not affected by this vulnerability is crucial for maintaining the security and availability of your services.

Timeline

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