CVE-2022-21569: Oracle MySQL Server DOS Vulnerability

CVE-2022-21569 Overview

CVE-2022-21569 is a denial of service vulnerability in the MySQL Server product of Oracle MySQL, specifically within the Server: Optimizer component. This easily exploitable vulnerability allows a low privileged attacker with network access via multiple protocols to compromise MySQL Server, resulting in the ability to cause a hang or frequently repeatable crash of the database service.

Critical Impact

Successful exploitation results in complete denial of service (DoS) of MySQL Server, causing service unavailability that can significantly impact business operations and dependent applications.

Affected Products

• Oracle MySQL Server versions 8.0.29 and prior
• NetApp Active IQ Unified Manager (VMware vSphere and Windows)
• NetApp OnCommand Insight
• NetApp OnCommand Workflow Automation
• NetApp SnapCenter

Discovery Timeline

• 2022-07-19 - CVE-2022-21569 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-21569

Vulnerability Analysis

This vulnerability resides in the Server: Optimizer component of MySQL Server. The optimizer is responsible for analyzing SQL queries and determining the most efficient execution plan. A flaw in this component allows attackers to craft queries that cause the database server to enter a hung state or trigger repeatable crashes.

The vulnerability is particularly concerning because it requires only low-level privileges to exploit, meaning that any authenticated user with basic database access could potentially trigger the denial of service condition. The attack can be executed remotely over the network using multiple protocols supported by MySQL Server.

Root Cause

The root cause stems from improper handling within the MySQL Server Optimizer component. When processing certain types of queries or query patterns, the optimizer fails to properly manage resources or handle edge cases, leading to service disruption. The specific implementation flaw allows malicious queries to consume resources inappropriately or trigger logic errors that result in server crashes.

Attack Vector

The attack is network-based and can be executed by any authenticated user with low privileges. An attacker would need valid credentials to connect to the MySQL Server instance, then send specially crafted SQL queries designed to trigger the vulnerability in the optimizer component. The attack requires no user interaction and can be repeated to maintain the denial of service condition.

The vulnerability affects availability only, with no impact on confidentiality or integrity of data stored in the database. However, the complete denial of service can have cascading effects on applications and services that depend on the MySQL Server instance.

Detection Methods for CVE-2022-21569

Indicators of Compromise

• Unexpected MySQL Server crashes or hangs, particularly when processing complex queries
• Unusual patterns in MySQL error logs indicating optimizer-related failures
• Repeated connection attempts followed by server unresponsiveness
• Abnormal CPU or memory consumption by the MySQL process during query optimization

Detection Strategies

• Monitor MySQL Server error logs for optimizer-related errors and crash reports
• Implement database query auditing to identify suspicious or malformed queries
• Deploy network monitoring to detect unusual patterns of database connections from low-privileged accounts
• Use SentinelOne Singularity to monitor for process crashes and abnormal behavior of MySQL daemon processes

Monitoring Recommendations

• Configure MySQL slow query log to capture queries that may be triggering optimizer issues
• Set up automated alerting for MySQL Server crashes or service restarts
• Monitor system metrics for the MySQL Server host, including CPU utilization spikes and memory consumption anomalies
• Implement database availability monitoring to detect service interruptions promptly

How to Mitigate CVE-2022-21569

Immediate Actions Required

• Upgrade MySQL Server to version 8.0.30 or later, which addresses this vulnerability
• Review and audit database user privileges, removing unnecessary access
• Implement query filtering or rate limiting at the application layer
• Consider deploying database activity monitoring solutions to detect exploit attempts

Patch Information

Oracle has released a security patch addressing this vulnerability as part of the Oracle July 2022 Critical Patch Update. Organizations using MySQL Server version 8.0.29 or earlier should upgrade to a patched version immediately.

For NetApp products affected by this vulnerability, refer to the NetApp Security Advisory for product-specific guidance and patch information.

Workarounds

• Restrict network access to MySQL Server to trusted hosts and networks only
• Implement strict privilege management to limit the number of users with database access
• Use database firewalls or proxy solutions to filter potentially malicious queries
• Enable MySQL Server resource limits to prevent excessive resource consumption from single sessions

# Configuration example: Restrict MySQL access to specific hosts
# In my.cnf or mysqld.cnf
[mysqld]
bind-address = 127.0.0.1
# Or restrict to specific network interface
# bind-address = 192.168.1.100

# Limit connections per user to reduce DoS impact
max_user_connections = 10

# Enable general query log for auditing (use cautiously in production)
general_log = 1
general_log_file = /var/log/mysql/mysql-queries.log