CVE-2025-50078: Oracle MySQL Server DML DOS Vulnerability

CVE-2025-50078 Overview

CVE-2025-50078 is a Denial of Service (DoS) vulnerability in the MySQL Server product of Oracle MySQL, specifically affecting the Server: DML component. This vulnerability allows a low-privileged attacker with network access to cause a complete denial of service against MySQL Server instances, resulting in system hangs or frequently repeatable crashes.

Critical Impact

Successful exploitation allows attackers to cause complete denial of service of MySQL Server, disrupting database availability for all dependent applications and services.

Affected Products

• Oracle MySQL Server versions 8.0.0 through 8.0.42
• Oracle MySQL Server versions 8.4.0 through 8.4.5
• Oracle MySQL Server versions 9.0.0 through 9.3.0

Discovery Timeline

• 2025-07-15 - CVE-2025-50078 published to NVD
• 2025-07-17 - Last updated in NVD database

Technical Details for CVE-2025-50078

Vulnerability Analysis

This vulnerability resides in the Data Manipulation Language (DML) component of MySQL Server. The flaw is classified as CWE-400 (Uncontrolled Resource Consumption), indicating that the server fails to properly limit resource consumption during certain DML operations. An authenticated attacker can exploit this weakness through multiple network protocols supported by MySQL, triggering excessive resource consumption that leads to server instability.

The vulnerability is easily exploitable, requiring only low-privilege database access. No user interaction is needed for successful exploitation, and the attack can be launched remotely over the network. While the vulnerability does not compromise data confidentiality or integrity, the availability impact is severe—attackers can reliably cause the MySQL Server to hang or crash repeatedly.

Root Cause

The underlying cause is classified as CWE-400: Uncontrolled Resource Consumption. The DML component fails to implement adequate safeguards against resource exhaustion, allowing malicious queries or operations to consume excessive server resources without proper throttling or termination mechanisms.

Attack Vector

The attack is network-based and can be executed through multiple protocols that MySQL Server supports. An attacker requires only low-privilege authentication to the database—essentially any valid database user account. The attack does not require any user interaction and can be automated for persistent denial of service.

The exploitation mechanism involves crafting specific DML operations that trigger the resource exhaustion condition in the server. When executed, these operations cause the MySQL Server process to either hang indefinitely or crash, requiring administrator intervention to restore service availability.

Detection Methods for CVE-2025-50078

Indicators of Compromise

• Unexpected MySQL Server crashes or service restarts with no apparent cause
• Database connection timeouts or failures across multiple client applications
• Unusual resource consumption patterns (CPU, memory) on MySQL Server hosts
• Error logs showing repeated crash dumps or out-of-memory conditions in DML processing

Detection Strategies

• Monitor MySQL error logs for crash signatures related to DML operations or resource exhaustion
• Implement query profiling to identify abnormal query patterns from authenticated users
• Configure alerting on MySQL Server availability metrics and unexpected restarts
• Review authentication logs for suspicious low-privilege account activity patterns

Monitoring Recommendations

• Enable MySQL Performance Schema to track resource-intensive queries
• Configure server health monitoring with automatic alerting on service interruptions
• Implement connection pooling metrics to detect availability degradation
• Monitor system resource utilization (CPU, memory) on database servers for anomalies

How to Mitigate CVE-2025-50078

Immediate Actions Required

• Upgrade MySQL Server to a patched version as specified in Oracle's July 2025 Critical Patch Update
• Review and restrict database user privileges to minimize the number of accounts that could exploit this vulnerability
• Implement network segmentation to limit which systems can connect to MySQL Server
• Enable query timeout limits to prevent long-running malicious operations

Patch Information

Oracle has released patches addressing this vulnerability in their July 2025 Critical Patch Update. Administrators should consult the Oracle Security Alert July 2025 for specific patch versions and upgrade instructions for affected MySQL Server releases.

Workarounds

• Implement strict network access controls to limit MySQL Server exposure to trusted hosts only
• Review and revoke unnecessary database user accounts, especially those with minimal auditing
• Configure resource limits using MySQL's max_execution_time and memory allocation settings
• Consider deploying MySQL behind a database firewall capable of query analysis and blocking

# Configuration example - MySQL resource limits
# Add to my.cnf or my.ini configuration file
[mysqld]
max_execution_time=30000
max_connections=150
max_user_connections=50
thread_stack=256K