CVE-2009-0505 in TXSeries
Summary
by MITRE
The CICS listener in IBM TXSeries for Multiplatforms 6.2 GA waits for a forcepurge acknowledgement from the CICS Application Server (CICSAS) after an eci response timeout, which might allow remote authenticated users to cause a denial of service (forcepurge handling delay), or have unspecified other impact, via vectors involving slow or nonexistent acknowledgement.
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Analysis
by VulDB Data Team • 08/28/2019
The vulnerability described in CVE-2009-0505 affects IBM TXSeries for Multiplatforms version 6.2 GA, specifically within the CICS listener component that manages communication between application servers and the CICS Application Server. This flaw resides in the forcepurge handling mechanism which is designed to manage cleanup operations when application responses exceed predetermined timeout thresholds. The CICS listener maintains a stateful connection management system that relies on proper acknowledgment protocols to ensure orderly termination of processes and resource cleanup. When an eci response timeout occurs, the system is expected to initiate a forcepurge sequence that requires confirmation from the CICS Application Server before proceeding with cleanup operations.
The technical implementation of this vulnerability stems from the listener's synchronous waiting behavior for forcepurge acknowledgments from the CICSAS component. Under normal operating conditions, when a timeout occurs during eci response processing, the system should immediately initiate forcepurge operations and proceed with cleanup regardless of whether an acknowledgment is received. However, the flaw causes the listener to indefinitely wait for an acknowledgment that may never arrive due to network delays, server unavailability, or other communication issues. This synchronous waiting pattern creates a condition where legitimate cleanup operations can be delayed or blocked entirely, effectively creating a denial of service scenario.
The operational impact of this vulnerability extends beyond simple denial of service to potentially affect system availability and stability in production environments. Remote authenticated users who can establish connections to the TXSeries listener can exploit this weakness by initiating sequences that cause the listener to wait indefinitely for acknowledgments. This behavior can result in resource exhaustion as the listener maintains pending connections and process states while waiting for non-arriving confirmations. The vulnerability may also create cascading effects where multiple delayed forcepurge operations consume system resources and potentially impact other legitimate operations within the CICS environment. The unspecified other impacts mentioned in the description suggest potential for additional security implications or system instability beyond the immediate denial of service condition.
This vulnerability aligns with CWE-400, which addresses "Uncontrolled Resource Consumption" and specifically relates to situations where systems fail to properly handle resource cleanup operations. The flaw demonstrates poor error handling and resource management practices within the transaction processing environment. From an adversarial perspective, this vulnerability maps to ATT&CK technique T1499.004, which covers "Endpoint Denial of Service" through resource exhaustion or process blocking. The authenticated nature of the attack vector indicates that exploitation requires valid credentials, but the impact can be significant as it affects the core transaction processing capabilities of the system. Organizations should consider implementing network segmentation and access controls to limit exposure, while also applying the vendor-provided patches to address the underlying forcepurge handling logic. The vulnerability underscores the importance of proper timeout management and asynchronous processing in mission-critical transaction processing environments where availability is paramount.