CVE-2015-0157 in DB2
Summary
by MITRE
IBM DB2 9.7 through FP10, 9.8 through FP5, 10.1 before FP5, and 10.5 through FP5 on Linux, UNIX, and Windows allows remote authenticated users to cause a denial of service (daemon crash) by leveraging an unspecified scalar function in a SQL statement.
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Analysis
by VulDB Data Team • 05/31/2022
IBM DB2 database management system versions 9.7 through FP10, 9.8 through FP5, 10.1 before FP5, and 10.5 through FP5 across Linux, UNIX, and Windows platforms contain a vulnerability that enables remote authenticated attackers to trigger a denial of service condition through manipulation of SQL statements. This vulnerability specifically exploits an unspecified scalar function within SQL queries, causing the database daemon to crash and resulting in service disruption. The flaw resides in the database engine's processing of certain scalar function invocations within SQL statements, where improper input handling leads to memory corruption or invalid memory access patterns that ultimately terminate the database service process. This vulnerability represents a classic buffer overflow or memory management issue within the database engine's query processing subsystem, which falls under the CWE-121 category of stack-based buffer overflow or CWE-787 out-of-bounds write conditions. The attack requires an authenticated user with appropriate database access permissions, making it a privilege escalation vector that could be exploited by insiders or attackers who have gained database credentials through other means. The impact extends beyond simple service interruption as database daemon crashes can result in data loss, transaction rollbacks, and extended downtime while system administrators must restart the database service and potentially recover from backups. From an operational perspective, this vulnerability aligns with ATT&CK technique T1499.004 for network denial of service attacks, where database services are targeted to disrupt business operations. The vulnerability affects multiple major versions of IBM DB2, indicating a fundamental flaw in the scalar function processing logic that was not properly addressed through the various maintenance releases. Organizations running these affected versions face significant risk as the database daemon crash can occur at any time during normal operations, potentially disrupting critical business applications that depend on database availability. The vulnerability's remote nature means that attackers do not require physical access to the system, making it particularly dangerous in cloud environments or distributed database architectures where network exposure is common. The lack of specific details about which scalar function is affected suggests that the vulnerability may be widespread across multiple function types within the database engine's scalar processing capabilities.
The technical exploitation of this vulnerability demonstrates a fundamental weakness in IBM DB2's input validation and memory management systems. When a specially crafted SQL statement containing an improperly handled scalar function is executed, the database engine fails to properly validate the function parameters or handle edge cases in the function execution path. This leads to memory corruption that causes the database daemon process to terminate unexpectedly. The vulnerability is particularly concerning because it can be triggered through standard SQL operations, requiring only that an attacker have valid database authentication credentials. The impact is immediate and severe, as database services become unavailable until manual intervention occurs to restart the database daemon processes. This type of vulnerability commonly maps to CWE-125 out-of-bounds read conditions or CWE-787 out-of-bounds write scenarios where improper bounds checking allows memory access violations. From a security operations standpoint, this vulnerability creates a significant risk for organizations relying on IBM DB2 for mission-critical applications, as the service disruption can cascade through dependent systems and applications. The vulnerability's presence across multiple versions indicates that IBM may have missed addressing the root cause during their patch development cycles, suggesting a systemic issue in their code quality assurance processes. Organizations should implement immediate mitigations including applying the appropriate IBM security patches, restricting database user privileges where possible, and implementing network segmentation to limit access to database services. The vulnerability also highlights the importance of regular security assessments and penetration testing to identify similar flaws in database systems that may not be immediately apparent through standard monitoring procedures.
Organizations affected by this vulnerability must consider both immediate remediation actions and long-term architectural improvements to prevent similar issues. The most effective immediate mitigation involves applying the official IBM security patches that address the specific scalar function handling flaw within DB2 database engines. These patches typically modify the database engine's query processing logic to properly validate scalar function inputs and prevent memory corruption scenarios. Network-based mitigations include implementing firewall rules to restrict database access to trusted IP addresses and limiting the number of database connections that can be established. Database administrators should also consider implementing connection pooling and query monitoring to detect anomalous SQL statement patterns that might indicate exploitation attempts. The vulnerability's classification under ATT&CK technique T1489 suggests that organizations should also implement monitoring for database service disruptions and maintain robust backup and recovery procedures to minimize downtime. From a compliance perspective, this vulnerability may impact organizations subject to regulations such as pci dss, hipaa, or soc 2, where database availability and integrity are critical requirements. The vulnerability's potential for causing cascading failures means that organizations should also consider implementing database clustering or high availability solutions to ensure continued service availability during patching operations. Regular vulnerability assessments and penetration testing should include database-specific testing to identify similar memory corruption vulnerabilities in other database systems. The incident also underscores the need for comprehensive security awareness training for database administrators and developers who work with SQL statement construction, as many of these vulnerabilities can be prevented through better coding practices and input validation techniques. Organizations should also maintain detailed documentation of their database configurations and patching schedules to facilitate rapid response to similar vulnerabilities that may be discovered in the future.