CVE-2025-36427
📋 TL;DR
IBM Db2 databases are vulnerable to denial of service attacks when processing specially crafted queries due to insufficient input validation. This affects Db2 for Linux, UNIX, Windows, and Db2 Connect Server installations. Attackers with database access can crash the Db2 service, disrupting database operations.
💻 Affected Systems
- IBM Db2 for Linux, UNIX and Windows
- IBM 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 service outage requiring manual restart, potentially causing extended business disruption and data unavailability.
Likely Case
Temporary service interruption affecting database-dependent applications until Db2 is restarted.
If Mitigated
Minimal impact with proper access controls and monitoring in place to detect and block malicious queries.
🎯 Exploit Status
Exploitation requires valid database credentials. The vulnerability is in query processing logic, making exploitation straightforward for authenticated users.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check IBM advisory for specific fixed versions
Vendor Advisory: https://www.ibm.com/support/pages/node/7257696
Restart Required: Yes
Instructions:
1. Review IBM advisory for affected versions. 2. Apply the appropriate fix pack or interim fix from IBM. 3. Restart Db2 services. 4. Test database functionality.
🔧 Temporary Workarounds
Restrict Database Access
allLimit database user privileges to only necessary functions and implement strict access controls.
REVOKE EXECUTE ON PROCEDURE sysproc.db2expln FROM PUBLIC;
REVOKE EXECUTE ON PROCEDURE sysproc.explain FROM PUBLIC;
Implement Query Monitoring
allMonitor and alert on unusual query patterns or repeated failed queries that could indicate exploitation attempts.
db2pd -db <dbname> -dynamic
db2 get snapshot for database on <dbname>
🧯 If You Can't Patch
- Implement strict principle of least privilege for all database users
- Deploy network segmentation and firewall rules to restrict Db2 access to trusted sources only
🔍 How to Verify
Check if Vulnerable:
Check Db2 version against IBM advisory: db2levelCheck Version:
db2levelVerify Fix Applied:
Verify applied fix pack: db2level and confirm version matches IBM's fixed versions📡 Detection & Monitoring
Log Indicators:
- Unexpected Db2 service crashes
- Abnormal query patterns in db2diag.log
- Repeated failed queries from single source
Network Indicators:
- Unusual database connection patterns
- Spike in database error responses
SIEM Query:
source="db2diag.log" AND ("crash" OR "abend" OR "unexpected termination")