CVE-2025-21548: MySQL Connector/Python Auth Bypass Flaw

CVE-2025-21548 Overview

CVE-2025-21548 is a resource exhaustion vulnerability affecting Oracle MySQL Connector/Python, a critical component used by Python applications to interface with MySQL databases. This vulnerability allows a high-privileged attacker with network access to compromise MySQL Connectors through multiple protocols, potentially resulting in unauthorized data manipulation, information disclosure, and denial of service conditions.

The vulnerability is classified under CWE-400 (Uncontrolled Resource Consumption), indicating that the affected component fails to properly limit resource utilization, which can be exploited to cause system degradation or complete service unavailability.

Critical Impact

Successful exploitation enables attackers to create, delete, or modify critical data, gain unauthorized read access to sensitive information, and cause complete denial of service through system hangs or crashes.

Affected Products

• Oracle MySQL Connector/Python version 9.1.0 and prior

Discovery Timeline

• 2025-01-21 - CVE-2025-21548 published to NVD
• 2025-06-18 - Last updated in NVD database

Technical Details for CVE-2025-21548

Vulnerability Analysis

This vulnerability exists within the Connector/Python component of Oracle MySQL Connectors. The flaw represents a resource exhaustion condition that can be triggered remotely over the network. While exploitation requires high privileges, the attack complexity is low and can be executed through multiple network protocols.

The vulnerability requires human interaction from a person other than the attacker to succeed, which limits certain attack scenarios but does not eliminate the risk entirely. Once exploited, the attacker gains significant capabilities: the ability to create, delete, or modify critical data stored within MySQL Connectors, read access to a subset of accessible data, and the capacity to induce complete denial of service conditions.

The resource exhaustion nature of this vulnerability (CWE-400) suggests that the Connector/Python component does not adequately constrain resource consumption during certain operations, allowing malicious actors to overwhelm system resources and disrupt normal functionality.

Root Cause

The root cause is classified as CWE-400 (Uncontrolled Resource Consumption). The MySQL Connector/Python component fails to properly implement resource limits or throttling mechanisms, allowing an attacker to trigger excessive resource consumption. This can manifest as memory exhaustion, CPU overutilization, or connection pool depletion, ultimately leading to service degradation or complete unavailability.

Attack Vector

The attack is network-based and can leverage multiple protocols supported by MySQL Connector/Python. An attacker with high-level privileges and network access to the target system can craft malicious requests or operations that exploit the resource exhaustion condition. The requirement for human interaction suggests that social engineering or user-initiated actions may be necessary to complete the attack chain.

Potential attack scenarios include manipulating database connection parameters, sending specially crafted queries that trigger excessive resource allocation, or exploiting authentication and session handling mechanisms within the connector.

Detection Methods for CVE-2025-21548

Indicators of Compromise

• Unusual spikes in memory consumption by Python applications using MySQL Connector/Python
• Abnormal CPU utilization patterns associated with database connection operations
• Unexpected connection pool exhaustion or connection timeout errors
• Application crashes or hangs during MySQL database interactions
• Unauthorized modifications to database records or schemas

Detection Strategies

• Monitor resource utilization metrics for Python applications interfacing with MySQL databases
• Implement logging and alerting for unusual database connection patterns and query behaviors
• Review access logs for high-privileged accounts performing atypical operations
• Deploy application performance monitoring to detect anomalous resource consumption

Monitoring Recommendations

• Enable detailed logging for MySQL Connector/Python operations and connection lifecycle events
• Configure resource usage thresholds and alerts for database-connected applications
• Monitor for repeated connection failures or timeout conditions that may indicate exploitation attempts
• Audit high-privileged account activities and correlate with application behavior anomalies

How to Mitigate CVE-2025-21548

Immediate Actions Required

• Review and apply the Oracle Critical Patch Update from January 2025 immediately
• Audit all systems running MySQL Connector/Python version 9.1.0 or earlier to identify vulnerable deployments
• Implement network segmentation to restrict access to systems using MySQL Connector/Python
• Review and minimize high-privileged account access to affected components
• Enable enhanced monitoring for affected applications pending patch deployment

Patch Information

Oracle has addressed this vulnerability in the January 2025 Critical Patch Update. Organizations should upgrade MySQL Connector/Python to the latest patched version as recommended in the Oracle Critical Patch Update January 2025. The patch resolves the resource exhaustion condition and implements proper resource management controls.

Workarounds

• Restrict network access to MySQL Connector/Python components using firewall rules and access control lists
• Implement resource quotas and limits at the operating system or container level for applications using the affected connector
• Reduce the number of high-privileged accounts with access to MySQL Connectors
• Deploy application-level rate limiting to prevent resource exhaustion attacks
• Consider using alternative database connectivity methods until patches can be applied

# Example: Restrict network access to MySQL services
# Add firewall rules to limit access to trusted sources only
iptables -A INPUT -p tcp --dport 3306 -s trusted_network/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 3306 -j DROP

# Example: Implement resource limits for Python applications (systemd)
# Add to service unit file [Service] section:
# MemoryLimit=512M
# CPUQuota=50%