CVE-2025-50079
📋 TL;DR
This vulnerability in MySQL Server's optimizer component allows authenticated high-privilege attackers to cause denial of service by crashing or hanging the database server. It affects MySQL versions 8.0.0-8.0.42, 8.4.0-8.4.5, and 9.0.0-9.3.0. Attackers need network access and administrative privileges to exploit this vulnerability.
💻 Affected Systems
- Oracle MySQL Server
📦 What is this software?
Mysql by Oracle
Mysql by Oracle
Mysql by Oracle
⚠️ Risk & Real-World Impact
Worst Case
Complete database server outage causing application downtime and service disruption
Likely Case
Database server crashes requiring restart, causing temporary service interruption
If Mitigated
Minimal impact due to proper access controls and monitoring
🎯 Exploit Status
CVSS indicates easily exploitable but requires high privileges
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 8.0.42, 8.4.5, and 9.3.0
Vendor Advisory: https://www.oracle.com/security-alerts/cpujul2025.html
Restart Required: Yes
Instructions:
1. Download latest MySQL patch from Oracle
2. Backup database
3. Apply patch following Oracle's upgrade procedures
4. Restart MySQL service
🔧 Temporary Workarounds
Restrict administrative access
allLimit network access to MySQL administrative accounts and interfaces
# Restrict MySQL port (default 3306) to trusted IPs
# Use firewall rules specific to your environment
Implement privilege separation
allUse least privilege principle for MySQL accounts
REVOKE ALL PRIVILEGES ON *.* FROM 'admin_user'@'%';
GRANT SELECT, INSERT, UPDATE, DELETE ON specific_db.* TO 'app_user'@'specific_host';
🧯 If You Can't Patch
- Implement strict network segmentation and firewall rules to limit MySQL access
- Enhance monitoring for unusual administrative activity and failed connection attempts
🔍 How to Verify
Check if Vulnerable:
Check MySQL version: SELECT VERSION(); and compare against affected rangesCheck Version:
mysql -u root -p -e 'SELECT VERSION();'Verify Fix Applied:
Verify version is above affected ranges: SELECT VERSION(); should show >8.0.42, >8.4.5, or >9.3.0📡 Detection & Monitoring
Log Indicators:
- Unexpected MySQL crashes or restarts
- Multiple failed connection attempts from single source
- Unusual optimizer-related errors in MySQL error log
Network Indicators:
- Multiple connection attempts to MySQL port 3306 from unusual sources
- Traffic patterns suggesting DoS attempts
SIEM Query:
source="mysql_error.log" AND ("crash" OR "hang" OR "optimizer")