CVE-2018-1786 in Spectrum Protect
Summary
by MITRE
IBM Spectrum Protect 7.1 and 8.1 dsmc and dsmcad processes incorrectly accumulate TCP/IP sockets in a CLOSE_WAIT state. This can cause TCP/IP resource leakage and may result in a denial of service. IBM X-Force ID: 148871.
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Analysis
by VulDB Data Team • 06/05/2023
The vulnerability identified as CVE-2018-1786 affects IBM Spectrum Protect versions 7.1 and 8.1, specifically impacting the dsmc and dsmcad processes that handle backup and recovery operations. This issue represents a classic resource management flaw where TCP/IP sockets fail to properly transition from established connection states to complete closure, resulting in persistent socket accumulation in the CLOSE_WAIT state. The vulnerability stems from improper socket lifecycle management within the application's network communication handling mechanisms, creating a condition where connections remain allocated in memory even after they should have been terminated.
The technical flaw manifests as a failure in the TCP connection state machine implementation where the dsmc and dsmcad processes do not adequately process the TCP FIN acknowledgment packets that signal the completion of a connection shutdown sequence. When a TCP connection enters the CLOSE_WAIT state, it indicates that the local side has received a FIN packet from the remote side and is waiting for the local application to close the connection properly. However, in this vulnerability, the application fails to complete the necessary cleanup operations, leaving the socket in a perpetually waiting state where it cannot be reused for new connections.
This socket accumulation creates significant operational impact by consuming system resources including file descriptors, memory allocations, and network buffer space. As the number of accumulated sockets increases, the system gradually depletes its available TCP/IP resources, eventually leading to connection failures and service unavailability. The vulnerability can be exploited to achieve a denial of service condition where legitimate backup operations fail due to resource exhaustion, potentially disrupting critical data protection workflows and causing business continuity issues.
The vulnerability aligns with CWE-404, which describes improper resource shutdown or release, and represents a classic case of resource leakage in network programming. From an ATT&CK perspective, this vulnerability could be leveraged in the context of resource exhaustion attacks, potentially falling under techniques related to service disruption and system resource compromise. The impact is particularly severe in environments where IBM Spectrum Protect handles high volumes of backup operations, as the accumulation of closed sockets can rapidly consume available system resources and degrade overall system performance.
Organizations should implement immediate mitigations including monitoring socket usage patterns and implementing connection timeout configurations to prevent indefinite socket accumulation. Regular system restarts of affected processes can provide temporary relief while permanent solutions involve applying the official IBM patches and updates that address the socket lifecycle management issues. Additionally, network administrators should consider implementing connection pooling strategies and monitoring tools that can detect and alert on unusual socket state patterns to prevent exploitation and maintain system stability.