CVE-2025-21579: Oracle MySQL Server DOS Vulnerability

CVE-2025-21579 Overview

CVE-2025-21579 is a denial of service vulnerability in the MySQL Server product of Oracle MySQL, specifically affecting the Server: Options component. This vulnerability allows a high-privileged attacker with network access to cause a complete denial of service condition, resulting in a hang or frequently repeatable crash of the MySQL Server.

Critical Impact

Successful exploitation enables attackers to cause complete denial of service (DoS) of MySQL Server, disrupting database availability and dependent applications.

Affected Products

• Oracle MySQL Server versions 8.0.0 through 8.0.41
• Oracle MySQL Server versions 8.4.0 through 8.4.4
• Oracle MySQL Server versions 9.0.0 through 9.2.0

Discovery Timeline

• 2025-04-15 - CVE-2025-21579 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2025-21579

Vulnerability Analysis

This vulnerability resides in the Server: Options component of Oracle MySQL Server. The flaw is classified under CWE-732 (Incorrect Permission Assignment for Critical Resource), indicating improper handling of permissions or configurations within the options processing functionality.

The vulnerability is easily exploitable, though it requires high-privileged access to the MySQL Server. An authenticated attacker with administrative privileges can leverage this flaw through multiple network protocols to induce a denial of service condition. The impact is limited to availability—there is no breach of confidentiality or integrity.

Root Cause

The root cause is traced to CWE-732, which involves incorrect permission assignment for critical resources. In the context of MySQL Server's Options component, this manifests as improper handling of server configuration options that can lead to resource exhaustion or an unhandled state causing the server process to crash or hang.

Attack Vector

The attack vector is network-based, allowing exploitation via multiple protocols supported by MySQL Server. An attacker must possess high privileges (such as administrative access) to execute this attack. The attack complexity is low, requiring no user interaction beyond the attacker's authenticated session.

The exploitation scenario involves a privileged user manipulating server options in a manner that triggers the vulnerability, causing the MySQL Server process to enter an unrecoverable state. This results in either a complete hang or a repeatable crash, effectively denying service to legitimate users and applications.

Detection Methods for CVE-2025-21579

Indicators of Compromise

• Unexpected MySQL Server crashes or hangs coinciding with administrative configuration changes
• Repeated server restarts without clear operational cause
• Anomalous queries or commands in MySQL logs from high-privileged accounts targeting server options
• Unusual network connections to MySQL administrative interfaces from unexpected sources

Detection Strategies

• Monitor MySQL error logs for crash patterns and server hang indicators
• Implement audit logging for all administrative actions, particularly those modifying server options
• Deploy database activity monitoring (DAM) solutions to track privileged user behavior
• Configure alerting for MySQL Server process terminations or unresponsive states

Monitoring Recommendations

• Enable MySQL's General Query Log and Slow Query Log to capture administrative activity
• Implement network monitoring to detect unusual traffic patterns to MySQL ports (3306, 33060)
• Set up process monitoring for mysqld to detect crashes, hangs, and unexpected restarts
• Review authentication logs for suspicious high-privilege account activity

How to Mitigate CVE-2025-21579

Immediate Actions Required

• Apply the latest Oracle Critical Patch Update (CPU) for April 2025 immediately
• Review and restrict high-privilege account access to only essential personnel
• Implement network segmentation to limit administrative access to MySQL Server
• Enable comprehensive audit logging for all administrative operations

Patch Information

Oracle has released security patches addressing this vulnerability in the Oracle Security Alert April 2025. Organizations should upgrade to patched versions:

• MySQL Server 8.0.42 or later (for 8.0.x series)
• MySQL Server 8.4.5 or later (for 8.4.x series)
• MySQL Server 9.2.1 or later (for 9.x series)

Additional information is available from the NetApp Security Advisory NTAP-20250502-0006.

Workarounds

• Restrict network access to MySQL Server administrative interfaces using firewall rules
• Implement principle of least privilege for database administrator accounts
• Enable MySQL's connection control plugin to limit failed authentication attempts
• Consider using MySQL Enterprise Firewall to monitor and control SQL statement execution

# Configuration example - Restrict MySQL network access
# Add to my.cnf or my.ini configuration file

[mysqld]
# Bind MySQL to specific trusted network interface only
bind-address = 127.0.0.1

# Enable audit logging for administrative actions
audit_log_policy = ALL

# Set connection limits to prevent abuse
max_connections = 100
max_user_connections = 10