CVE-2025-50084
📋 TL;DR
A vulnerability in MySQL Server's optimizer component allows high-privileged attackers with network access to cause denial of service by crashing or hanging the server. Affects MySQL Server versions 8.0.0-8.0.42, 8.4.0-8.4.5, and 9.0.0-9.3.0.
💻 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 unavailability of MySQL Server leading to application downtime and data inaccessibility
Likely Case
Service disruption requiring restart of MySQL Server
If Mitigated
Limited impact due to proper access controls and monitoring
🎯 Exploit Status
CVSS indicates easily exploitable but requires high-privileged access
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply patches from Oracle CPU July 2025
Vendor Advisory: https://www.oracle.com/security-alerts/cpujul2025.html
Restart Required: Yes
Instructions:
1. Download appropriate patch from Oracle 2. Apply patch following Oracle documentation 3. Restart MySQL Server 4. Verify patch application
🔧 Temporary Workarounds
Restrict network access
allLimit MySQL Server network exposure to trusted hosts only
# In my.cnf: bind-address = 127.0.0.1
# Or use firewall: iptables -A INPUT -p tcp --dport 3306 -s trusted_ip -j ACCEPT
Implement least privilege
allReview and reduce high-privileged MySQL accounts
SHOW GRANTS FOR 'user'@'host';
REVOKE SUPER, PROCESS, SHUTDOWN FROM 'user'@'host';
🧯 If You Can't Patch
- Implement strict network segmentation and firewall rules
- Enforce strong authentication and monitor privileged account usage
🔍 How to Verify
Check if Vulnerable:
Check MySQL version: SELECT VERSION(); and compare with affected rangesCheck Version:
mysql -e "SELECT VERSION();"Verify Fix Applied:
Verify version is above affected ranges and check Oracle patch documentation📡 Detection & Monitoring
Log Indicators:
- Unexpected MySQL crashes
- Server hang events
- Error logs showing optimizer-related failures
Network Indicators:
- Multiple connection attempts from single source followed by service disruption
SIEM Query:
source="mysql_error.log" AND ("crash" OR "hang" OR "optimizer")