When it comes to database security, most people focus on the server – but client-side software can be just as risky. In this exclusive deep dive, we unpack CVE-2023-22053, a vulnerability in Oracle MySQL Server’s client programs that may let low-privilege attackers cause denial of service or even read data they’re not supposed to access.

What Is CVE-2023-22053?

CVE-2023-22053 is a security vulnerability discovered in the Client programs component of Oracle MySQL Server. It affects the following MySQL versions:

8..33 and prior

The vulnerability allows a low privileged attacker with network access to crash the MySQL Server or gain unauthorized read access to sensitive data by exploiting how client programs interact with the server. This flaw has a CVSS 3.1 base score of 5.9 (Medium).

- CVSS Vector: AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H
- Impact: Confidentiality (read data); Availability (server crash/denial of service)

Real-World Impact

An attacker who can connect to the MySQL server (even remotely, if the server allows it) – but doesn’t have high privilege – could:

- Cause a server crash: leading to a denial of service where the database is unavailable until restarted.
- Read protected data: in some situations, access data that should not be available to their user account.

This is a big deal for multi-tenant environments, web hosting, managed databases, or any scenario where you have untrusted users or customers connecting to your database.

Technical Details: How Can This Flaw Be Exploited?

The exact technical details are not public (as of writing), but based on Oracle’s advisory and community analysis, the flaw lies in the way MySQL client tools process responses from the server.

Vulnerable client programs could send specially crafted inputs to the MySQL Server, causing it to either:

Enter an invalid state and crash (denial of service).

For example, the attacker might use tools such as mysql or a crafted script to trigger problematic server behavior:

Sends a specially crafted request:

This could be an SQL query or protocol data packet that abuses a parsing or error-handling logic flaw.

Example: Code Snippet Trigger (Sample, Not Real Exploit)

Below is a hypothetical Python PoC that simulates how one might send a malicious payload using pymysql:

import pymysql

try:
    conn = pymysql.connect(
        host='victims.mysql.server',
        user='lowpriv_user',
        password='password',
        database='test'
    )
    cursor = conn.cursor()
    # Potentially exploitative query – substitute with real payload once available
    cursor.execute('SELECT /*!99999 vulnerable_func() */ FROM information_schema.tables;')
except Exception as ex:
    print(f'Crash or data leak observed: {ex}')
finally:
    cursor.close()
    conn.close()

> Note: The exact payload would depend on the specific bug. Replace vulnerable_func() or other parts with the known vector when it becomes public.

MySQL 8..34 or later

Find full details on Oracle’s advisory page:
🔗 Oracle Critical Patch Update Advisory - July 2023

References and Resources

- NVD CVE-2023-22053 Detail
- Oracle CPU Advisory (July 2023)
- MySQL Downloads - Latest Releases
- Public Vulnerability Database entry

Final Thoughts

CVE-2023-22053 is a powerful reminder that database security is more than just locking down server-side accounts and tables. The way client programs talk to the server can open up “side doors” for data leaks or denial of service, especially if you’re running older MySQL versions.

Upgrade now — and keep an eye on both client and server changelogs. For more updates and in-depth analysis of emerging threats, stay tuned!


*Original research by [YourName], exclusive for this site. Please credit if shared.*

Timeline

Published on: 07/18/2023 21:15:00 UTC
Last modified on: 09/16/2023 04:15:00 UTC