CVE-2015-8523 in Tivoli Storage Manager Fastback
Summary
by MITRE
The server in IBM Tivoli Storage Manager FastBack 5.5.x and 6.x before 6.1.12.2 allows remote attackers to cause a denial of service (service crash) via crafted packets to a TCP port.
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Analysis
by VulDB Data Team • 02/03/2019
The vulnerability identified as CVE-2015-8523 affects IBM Tivoli Storage Manager FastBack versions 5.5.x and 6.x prior to 6.1.12.2, representing a critical denial of service weakness that can be exploited remotely. This flaw exists within the server component of the FastBack storage management solution, which is designed for backup and recovery operations in enterprise environments. The vulnerability stems from inadequate input validation mechanisms within the TCP port handling logic, where the system fails to properly process malformed or crafted network packets sent to its listening ports. This represents a classic buffer over-read or improper input handling vulnerability that can be leveraged by remote attackers to disrupt service availability. The affected system architecture processes network traffic through TCP connections, and the flaw manifests when the server receives specially crafted packets that exceed expected data boundaries or contain malformed structures. According to CWE classification, this vulnerability aligns with CWE-129, which covers improper validation of array indices, and CWE-125, which addresses out-of-bounds read conditions. The ATT&CK framework categorizes this as a denial of service attack using network protocols, specifically falling under the technique of network denial of service through malformed packets.
The technical exploitation of this vulnerability requires an attacker to send specifically crafted packets to one of the TCP ports utilized by the IBM Tivoli Storage Manager FastBack server. These packets are designed to trigger memory corruption or state inconsistencies within the server application's network processing routines. When the server attempts to parse these malformed packets, it encounters unexpected data structures that cause the application to crash or become unresponsive, effectively rendering the backup and recovery services unavailable. The impact extends beyond simple service disruption as the FastBack server is typically integral to enterprise backup operations, making this vulnerability particularly dangerous in production environments where data protection services are critical. The vulnerability affects the server's ability to maintain stable network connections and process legitimate backup requests, potentially leading to extended downtime for critical data protection infrastructure.
The operational impact of CVE-2015-8523 can be severe for organizations relying on IBM Tivoli Storage Manager FastBack for their backup and recovery operations. Service disruption caused by this vulnerability can lead to extended periods where backup operations cannot be performed, potentially resulting in data loss scenarios if backup windows are missed. The remote nature of the attack means that adversaries can exploit this weakness from external networks without requiring physical access or authentication credentials, making the vulnerability particularly concerning for enterprise security. Organizations may experience cascading effects as backup failures can impact disaster recovery planning, compliance requirements, and overall data protection strategies. The vulnerability's presence in multiple versions of the software increases the attack surface and complicates remediation efforts, as organizations must assess their deployment environments and determine which systems are vulnerable. System administrators face the challenge of maintaining service availability while applying patches or implementing workarounds, potentially during critical backup windows.
Mitigation strategies for CVE-2015-8523 should prioritize immediate patch application to IBM Tivoli Storage Manager FastBack versions 6.1.12.2 and later, which contain the necessary security fixes to address the input validation issues. Network segmentation and access controls should be implemented to restrict unauthorized access to the affected TCP ports, limiting exposure to potential attackers. Organizations should consider implementing intrusion detection systems that can identify and alert on malformed packet patterns targeting the vulnerable service ports. Regular network monitoring should be established to detect unusual traffic patterns that might indicate exploitation attempts. System administrators should also implement proper logging and monitoring of server processes to quickly identify when service disruptions occur. Additional defensive measures include configuring firewalls to restrict access to the FastBack server ports from trusted networks only, implementing network access control lists, and establishing incident response procedures specifically for handling denial of service attacks. The vulnerability highlights the importance of maintaining up-to-date security patches and conducting regular vulnerability assessments of enterprise storage management solutions to prevent exploitation of known weaknesses.