CVE-2023-22053: Oracle MySQL Server DOS Vulnerability

CVE-2023-22053 Overview

CVE-2023-22053 is a vulnerability in the MySQL Server product of Oracle MySQL, specifically affecting the Client programs component. This vulnerability allows a low-privileged attacker with network access via multiple protocols to compromise MySQL Server, potentially causing denial of service conditions and unauthorized data access.

The vulnerability is difficult to exploit but can result in a complete denial of service (hang or frequently repeatable crash) of MySQL Server, as well as unauthorized read access to a subset of MySQL Server accessible data. Organizations running affected MySQL Server versions should prioritize assessment and remediation.

Critical Impact

Successful exploitation can cause complete denial of service of MySQL Server and enable unauthorized read access to sensitive data stored in the database.

Affected Products

• Oracle MySQL Server versions 5.7.42 and prior
• Oracle MySQL Server versions 8.0.33 and prior
• Fedora 37, 38, and 39 (through packaged MySQL)
• NetApp Active IQ Unified Manager (VMware vSphere and Windows)
• NetApp OnCommand Insight
• NetApp OnCommand Workflow Automation
• NetApp SnapCenter

Discovery Timeline

• July 18, 2023 - CVE-2023-22053 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2023-22053

Vulnerability Analysis

This vulnerability resides in the Client programs component of Oracle MySQL Server. The flaw allows an authenticated attacker with low privileges to trigger denial of service conditions or gain unauthorized read access to database contents. The attack requires network access but can be executed via multiple protocols supported by MySQL.

The vulnerability has dual impacts: availability and confidentiality. From an availability perspective, successful exploitation can cause the MySQL Server to hang or crash repeatedly, resulting in complete denial of service. From a confidentiality standpoint, attackers may gain unauthorized read access to a subset of data within the MySQL Server.

While the attack complexity is high (requiring specific conditions to be met), the low privilege requirement means that any authenticated user with basic database access could potentially exploit this vulnerability.

Root Cause

The exact technical root cause has not been publicly disclosed by Oracle (classified as NVD-CWE-noinfo). However, the vulnerability affects the Client programs component, suggesting improper handling of client-server communication that can be abused to destabilize the server or leak information.

Based on the impact profile (availability and confidentiality without integrity impact), the vulnerability likely involves improper resource management or boundary checking in client request processing that can be triggered by malformed or specially crafted client interactions.

Attack Vector

The attack is network-based and can be executed through multiple protocols supported by MySQL Server. The attacker requires:

1. Network access to the MySQL Server instance
2. Valid credentials with low-privilege access (basic authentication)
3. Ability to send specially crafted requests through MySQL client protocols

The attack does not require user interaction, meaning it can be executed programmatically once the attacker has network access and valid credentials. The vulnerability affects the unchanged scope, meaning the impact is contained within the MySQL Server component itself.

Due to the sensitive nature of this vulnerability and Oracle's responsible disclosure practices, no public proof-of-concept code has been released. The vulnerability manifests in the client programs component during client-server communication. Organizations should refer to the Oracle Security Alert for July 2023 for authoritative technical guidance.

Detection Methods for CVE-2023-22053

Indicators of Compromise

• Unexpected MySQL Server crashes or hangs, particularly during client connection activity
• Repeated restart events in MySQL error logs without clear cause
• Unusual query patterns from low-privileged users accessing data beyond their normal scope
• Elevated connection attempts or abnormal client program behavior in MySQL logs

Detection Strategies

• Monitor MySQL error logs for repeated crash signatures or hang conditions that correlate with client activity
• Implement query auditing to detect unusual data access patterns from low-privileged accounts
• Deploy network monitoring to identify anomalous MySQL protocol traffic patterns
• Enable MySQL General Query Log (temporarily) during investigation to capture suspicious client interactions
• Use SentinelOne Singularity to monitor for process crashes and abnormal MySQL Server behavior

Monitoring Recommendations

• Configure alerting for MySQL Server process crashes or unexpected restarts
• Establish baseline metrics for MySQL Server availability and alert on deviations
• Monitor database audit logs for unauthorized data access attempts
• Implement connection logging to track client program interactions with the server
• Use SentinelOne's real-time monitoring capabilities to detect exploitation attempts targeting MySQL infrastructure

How to Mitigate CVE-2023-22053

Immediate Actions Required

• Upgrade MySQL Server to version 8.0.34 or later (for 8.0.x branch) or 5.7.43 or later (for 5.7.x branch)
• Review and restrict network access to MySQL Server instances using firewall rules
• Audit user accounts and remove unnecessary low-privileged access where possible
• Implement network segmentation to limit exposure of MySQL Server to trusted networks only
• Apply vendor patches for affected NetApp and Fedora products

Patch Information

Oracle has addressed this vulnerability in their July 2023 Critical Patch Update. Administrators should apply the appropriate patches based on their MySQL Server version:

• For MySQL 8.0.x: Upgrade to version 8.0.34 or later
• For MySQL 5.7.x: Upgrade to version 5.7.43 or later

Detailed patch information is available in the Oracle Security Alert - July 2023. NetApp has also released advisories for affected products, available at their Security Advisory Portal.

For Fedora users, updated MySQL packages are available through the standard package management system. Refer to the Fedora package announcements for specific update instructions.

Workarounds

• Restrict network access to MySQL Server to only trusted hosts and networks
• Implement strict principle of least privilege for all database user accounts
• Enable MySQL Server connection rate limiting to reduce potential DoS impact
• Consider deploying MySQL behind a proxy that can filter malicious requests
• Monitor and log all database connections for forensic analysis capabilities

# Restrict MySQL access to specific trusted networks
# Add to MySQL configuration (my.cnf or my.ini)
[mysqld]
bind-address = 127.0.0.1
# Or bind to specific internal network interface

# Review and audit user privileges
mysql -u root -p -e "SELECT user, host, authentication_string FROM mysql.user;"

# Revoke unnecessary privileges from low-privileged users
# REVOKE ALL PRIVILEGES ON sensitive_db.* FROM 'limited_user'@'%';

# Enable general query log for investigation (use temporarily)
# SET GLOBAL general_log = 'ON';
# SET GLOBAL general_log_file = '/var/log/mysql/mysql-general.log';