CVE-2025-30682
📋 TL;DR
A vulnerability in MySQL Server's optimizer component allows authenticated attackers with low privileges to cause denial of service by crashing or hanging the database server. This affects MySQL versions 8.0.0-8.0.41, 8.4.0-8.4.4, and 9.0.0-9.2.0. Attackers need network access and valid credentials to exploit this issue.
💻 Affected Systems
- Oracle MySQL Server
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete database unavailability causing application downtime, data loss from interrupted transactions, and cascading failures in dependent systems.
Likely Case
Periodic database crashes requiring manual restart, degraded application performance, and potential data corruption from interrupted operations.
If Mitigated
Limited impact with proper network segmentation and privilege management, though successful exploitation still causes service disruption.
🎯 Exploit Status
CVSS indicates 'easily exploitable' with low attack complexity. Requires authenticated access but minimal technical skill to execute.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to MySQL 8.0.42, 8.4.5, or 9.2.1 or later
Vendor Advisory: https://www.oracle.com/security-alerts/cpuapr2025.html
Restart Required: Yes
Instructions:
1. Backup databases and configuration. 2. Download patched version from Oracle. 3. Stop MySQL service. 4. Install update. 5. Restart MySQL service. 6. Verify version and functionality.
🔧 Temporary Workarounds
Network Access Restriction
linuxLimit MySQL port access to only trusted application servers and administrative systems
iptables -A INPUT -p tcp --dport 3306 -s trusted_ip -j ACCEPT
iptables -A INPUT -p tcp --dport 3306 -j DROP
Privilege Minimization
allReview and reduce database user privileges to minimum required for applications
REVOKE ALL PRIVILEGES ON *.* FROM 'username'@'host';
GRANT SELECT, INSERT ON database.table TO 'username'@'host';
🧯 If You Can't Patch
- Implement strict network segmentation and firewall rules to limit MySQL access
- Enforce principle of least privilege for all database users and monitor for suspicious activity
🔍 How to Verify
Check if Vulnerable:
Run 'SELECT VERSION();' in MySQL and compare against affected version rangesCheck Version:
mysql --version OR SELECT VERSION();Verify Fix Applied:
Confirm version is 8.0.42+, 8.4.5+, or 9.2.1+ using 'SELECT VERSION();'📡 Detection & Monitoring
Log Indicators:
- Unexpected MySQL crashes/restarts
- Error logs showing optimizer-related failures
- Multiple failed connection attempts from single source
Network Indicators:
- Unusual query patterns from authenticated users
- Spike in database errors followed by service restart
SIEM Query:
source="mysql_error.log" AND ("crash" OR "segfault" OR "optimizer")