CVE-2025-36407 Overview
IBM Db2 for Linux, UNIX and Windows (including Db2 Connect Server) contains a denial of service vulnerability caused by improper neutralization of special elements in data query logic. A local user with database access can exploit this flaw to cause a denial of service condition, disrupting database availability for legitimate users and applications.
Critical Impact
Local attackers can exploit improper input validation in query processing to trigger denial of service conditions, potentially disrupting critical database operations and business continuity.
Affected Products
- IBM Db2 for Linux 11.5.0 - 11.5.9
- IBM Db2 for UNIX 11.5.0 - 11.5.9
- IBM Db2 for Windows 11.5.0 - 11.5.9
- IBM Db2 for Linux 12.1.0 - 12.1.3
- IBM Db2 for UNIX 12.1.0 - 12.1.3
- IBM Db2 for Windows 12.1.0 - 12.1.3
- IBM Db2 Connect Server (affected versions)
Discovery Timeline
- 2026-01-30 - CVE-2025-36407 published to NVD
- 2026-02-05 - Last updated in NVD database
Technical Details for CVE-2025-36407
Vulnerability Analysis
This vulnerability is classified under CWE-1284 (Improper Validation of Specified Quantity in Input), indicating that the IBM Db2 database engine fails to properly validate or neutralize special elements within data query logic before processing. The flaw requires local access to the system, meaning an attacker must have some level of authenticated access to the database environment to exploit this issue.
The attack can be executed with low complexity and does not require user interaction, making it relatively straightforward for an authenticated local user to trigger. While the vulnerability does not impact data confidentiality or integrity, it poses a significant risk to system availability by allowing attackers to crash or hang database processes.
Root Cause
The root cause of CVE-2025-36407 lies in the improper neutralization of special elements within the data query logic processing component of IBM Db2. When handling certain query inputs, the database engine fails to adequately validate or sanitize special characters or sequences, allowing malformed queries to disrupt normal database operations.
This type of input validation flaw occurs when the application does not properly check the quantity, size, or format of input data before using it in operations, leading to unexpected behavior that can crash the database service.
Attack Vector
The attack vector for this vulnerability is local, requiring the attacker to have authenticated access to the system running IBM Db2. An attacker with valid database credentials or local system access can craft malicious queries containing special elements that are not properly neutralized by the database engine.
When such a query is processed, it can cause the Db2 service to enter an unresponsive state or crash entirely, resulting in denial of service for all users relying on that database instance. The attacker does not need elevated privileges beyond standard database access to execute this attack.
Detection Methods for CVE-2025-36407
Indicators of Compromise
- Unexpected Db2 service crashes or restarts without apparent cause
- Unusual query patterns containing special characters or malformed syntax in database logs
- Repeated connection timeouts or database unavailability events
- Spike in failed or abnormal query execution attempts from specific user accounts
Detection Strategies
- Monitor Db2 diagnostic logs (db2diag.log) for error messages indicating query processing failures or service interruptions
- Implement database activity monitoring to detect anomalous query patterns from local users
- Configure alerting on Db2 service availability and restart events
- Review authentication logs for unusual local access patterns preceding service disruptions
Monitoring Recommendations
- Enable comprehensive query logging to capture potentially malicious query attempts
- Set up real-time monitoring for Db2 process health and resource utilization
- Configure SentinelOne agents to monitor for abnormal database process behavior
- Establish baseline metrics for normal database operations to detect deviations
How to Mitigate CVE-2025-36407
Immediate Actions Required
- Review and apply the latest security patches from IBM for affected Db2 versions
- Audit local user access to Db2 databases and implement least-privilege principles
- Monitor database systems for signs of exploitation or unusual activity
- Prepare incident response procedures for potential denial of service events
Patch Information
IBM has released a security advisory addressing this vulnerability. Organizations running affected versions of IBM Db2 should review the IBM Security Advisory and apply the recommended patches as soon as possible.
Affected version ranges:
- IBM Db2 11.5.0 through 11.5.9
- IBM Db2 12.1.0 through 12.1.3
Workarounds
- Restrict local access to Db2 database servers to only essential personnel and applications
- Implement additional network segmentation to limit exposure of database systems
- Enable enhanced auditing and monitoring to detect exploitation attempts before service disruption
- Consider implementing application-layer query filtering as a defense-in-depth measure
# Example: Review Db2 version to determine if patching is required
db2level
# Example: Check current user access privileges
db2 "SELECT * FROM SYSCAT.DBAUTH"
# Example: Enable diagnostic logging for enhanced monitoring
db2 update dbm cfg using DIAGLEVEL 4
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
