CVE-2019-4101 in DB2
Summary
by MITRE
IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 10.1, 10.5, and 11.1 is vulnerable to a denial of service. Users that have both EXECUTE on PD_GET_DIAG_HIST and access to the diagnostic directory on the DB2 server can cause the instance to crash. IBM X-Force ID: 158091.
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Analysis
by VulDB Data Team • 10/09/2023
IBM DB2 database systems across multiple operating platforms contain a critical denial of service vulnerability that stems from improper handling of diagnostic data processing. The flaw specifically affects versions 10.1, 10.5, and 11.1 of the database server software, including the DB2 Connect Server component. This vulnerability manifests when authenticated users possess both EXECUTE privileges on the PD_GET_DIAG_HIST stored procedure and direct access to the diagnostic directory on the DB2 server instance. The technical implementation of this flaw involves the database server's insufficient validation of diagnostic history data during processing, which allows malicious or unauthorized users to craft specific inputs that trigger abnormal termination conditions within the database instance. This behavior aligns with CWE-248, an unchecked exception vulnerability where an exception is thrown but not properly handled, leading to application instability and potential system crashes.
The operational impact of this vulnerability extends beyond simple service disruption as it represents a significant security weakness that can be exploited by attackers with minimal privileges to cause system-wide database outages. When exploited successfully, the vulnerability results in complete database instance crashes that require manual intervention for recovery, potentially leading to extended downtime and data availability issues for organizations relying on these database systems. The attack vector requires specific preconditions including both the EXECUTE permission on the PD_GET_DIAG_HIST procedure and filesystem access to the diagnostic directory, making it moderately accessible to users with legitimate database access privileges who may have elevated permissions. This vulnerability falls under the ATT&CK technique T1499.004 for Network Denial of Service, as it specifically targets database instance availability through controlled input manipulation.
Organizations should implement immediate mitigations including restricting EXECUTE permissions on the PD_GET_DIAG_HIST stored procedure to only essential administrative users, implementing proper access controls for diagnostic directories, and applying the relevant IBM security patches as soon as they become available. The vulnerability demonstrates the importance of proper input validation and exception handling in database server applications, particularly when dealing with diagnostic and monitoring functions that process potentially untrusted data from various sources. System administrators should also consider implementing monitoring solutions to detect unusual patterns of diagnostic data access that might indicate attempted exploitation of this vulnerability. The flaw highlights the need for comprehensive privilege management and principle of least privilege enforcement in database environments, as the vulnerability can be exploited by users who have legitimate access to database functionality but should not have the ability to cause system-wide crashes through diagnostic data processing.