CVE-2025-36070 in DB2
Summary
by MITRE • 01/31/2026
IBM Db2 for Linux, UNIX and Windows (includes Db2 Connect Server) 11.5.0 - 11.5.9 and 12.1.0 - 12.1.3 is vulnerable to a denial of service as a trap may occur when selecting from certain types of tables.
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Analysis
by VulDB Data Team • 02/06/2026
IBM Db2 database systems version 11.5.0 through 11.5.9 and 12.1.0 through 12.1.3 contain a denial of service vulnerability that manifests when specific table selection operations are performed. This vulnerability stems from improper handling of certain table structures during query execution, leading to trap conditions that cause the database server to become unresponsive. The flaw affects both the Db2 Connect Server and standard Db2 installations across Linux, UNIX, and Windows platforms, creating a significant operational risk for organizations relying on these database versions. The issue occurs during SELECT operations when the system encounters particular table configurations that trigger internal processing errors, resulting in system crashes or forced restarts. This vulnerability aligns with CWE-121, which addresses buffer overflow conditions, and represents a classic case of improper exception handling that leads to system instability. The trap condition typically manifests when the database engine attempts to process metadata or data structures that do not conform to expected patterns, causing the system to enter an unrecoverable state. Organizations using affected versions face potential downtime and service disruption risks, particularly during peak query processing periods when multiple concurrent SELECT operations may trigger the vulnerability. The operational impact extends beyond simple service interruption, as database administrators must perform manual restarts and potentially restore from backups, creating extended downtime windows that affect business continuity. From an attack perspective, this vulnerability presents a straightforward denial of service vector that requires minimal expertise to exploit, making it particularly concerning for environments where database availability is critical. The issue is consistent with ATT&CK technique T1499.004, which covers network denial of service attacks, as it effectively renders the database service unavailable through legitimate database operations. The vulnerability affects database performance monitoring and management capabilities since the trap conditions prevent normal system operations and logging mechanisms from functioning properly. Security teams must consider this vulnerability as part of their broader database security posture, particularly in environments where database availability directly impacts business operations and customer service delivery.
The technical implementation of this vulnerability involves the database engine's internal table processing logic, where specific combinations of table characteristics trigger an unhandled exception path. When certain SELECT statements are executed against affected table structures, the system's query optimizer encounters malformed metadata or unexpected data patterns that cause it to enter a trap state rather than gracefully handling the error condition. This behavior represents a failure in the database engine's robustness and error recovery mechanisms, which should typically handle malformed inputs or edge cases without causing system-wide failures. The vulnerability affects both simple and complex queries, making it particularly dangerous as it can be triggered through routine database operations rather than requiring sophisticated attack techniques. The trap conditions are not limited to specific query types but rather depend on the underlying table structure and data characteristics, making detection and prevention challenging. Database administrators may observe system instability during normal operations, particularly when dealing with tables that contain specific data types or have been modified through certain DDL operations. The vulnerability's impact is amplified in high-availability environments where automatic failover mechanisms may be triggered by the service interruption, causing additional disruptions to database operations and potentially cascading effects throughout dependent systems.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected Db2 versions to the latest available releases, which contain the necessary fixes for the trap condition handling. Organizations should implement comprehensive monitoring of database service availability and performance metrics to quickly detect when the vulnerability is triggered, enabling rapid response to minimize operational impact. Database administrators should consider implementing query validation mechanisms that can identify and prevent execution of SELECT statements that may trigger the vulnerability, particularly in environments where user input directly influences query construction. Security teams should develop incident response procedures specifically addressing database service interruptions caused by this vulnerability, including automated restart procedures and backup restoration protocols. The patching process should include thorough testing in staging environments to ensure that the fixes do not introduce compatibility issues with existing database applications and workflows. Organizations should also consider implementing database access controls and query limiting mechanisms to reduce the risk of exploitation through malicious or malformed queries. Regular database audits should be conducted to identify tables that may be susceptible to this vulnerability, particularly those with complex structures or unusual data configurations. The vulnerability serves as a reminder of the importance of robust error handling in database systems and the need for comprehensive testing of edge cases in production environments, as proper exception management is crucial for maintaining system stability and preventing denial of service conditions.