CVE-2025-36009
📋 TL;DR
This vulnerability in IBM Db2 allows authenticated users to cause a denial of service by excessively using a global variable. It affects IBM Db2 for Linux, UNIX and Windows, including DB2 Connect Server. Attackers with database credentials can exploit this to disrupt database availability.
💻 Affected Systems
- IBM Db2 for Linux, UNIX and Windows
- DB2 Connect Server
📦 What is this software?
Db2 by Ibm
Db2 by Ibm
Db2 by Ibm
Db2 by Ibm
Db2 by Ibm
Db2 by Ibm
⚠️ Risk & Real-World Impact
Worst Case
Complete database unavailability affecting all dependent applications and services
Likely Case
Database service disruption requiring restart, causing temporary application downtime
If Mitigated
Minimal impact with proper authentication controls and monitoring
🎯 Exploit Status
Requires authenticated database access but exploitation appears straightforward based on CWE-1284 description
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check IBM advisory for specific fixed versions
Vendor Advisory: https://www.ibm.com/support/pages/node/7257695
Restart Required: Yes
Instructions:
1. Review IBM advisory for affected versions. 2. Apply the appropriate fix pack or interim fix. 3. Restart Db2 services. 4. Test database functionality.
🔧 Temporary Workarounds
Restrict database user privileges
allLimit user permissions to reduce attack surface
-- Use Db2 commands to review and restrict user privileges
-- Example: REVOKE EXECUTE ON PROCEDURE vulnerable_procedure FROM USER attacker
Implement connection rate limiting
allLimit connection attempts and resource usage per user
-- Configure Db2 connection and resource limits
-- Set MAX_CONNECTIONS and other resource constraints
🧯 If You Can't Patch
- Implement strict access controls and least privilege principles
- Monitor database logs for unusual global variable usage patterns
🔍 How to Verify
Check if Vulnerable:
Check Db2 version against IBM advisory and verify if running affected versionCheck Version:
db2level (on Db2 command line) or SELECT SERVICE_LEVEL, FIXPACK_NUM FROM SYSIBMADM.ENV_INST_INFOVerify Fix Applied:
Verify Db2 version after patching matches fixed version in advisory and test database functionality📡 Detection & Monitoring
Log Indicators:
- Excessive database connection attempts
- Unusual global variable access patterns
- Database crash or restart events
Network Indicators:
- Increased database connection traffic from single source
- Database service unavailability alerts
SIEM Query:
source="db2*" AND ("crash" OR "restart" OR "denial" OR "excessive")