CVE-2015-8520 in Tivoli Storage Manager Fastback
Summary
by MITRE
Buffer overflow in the server in IBM Tivoli Storage Manager FastBack 5.5.x and 6.x before 6.1.12.2 allows remote attackers to execute arbitrary code via a crafted command, a different vulnerability than CVE-2015-8519, CVE-2015-8521, and CVE-2015-8522.
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Analysis
by VulDB Data Team • 02/03/2019
The vulnerability identified as CVE-2015-8520 represents a critical buffer overflow flaw within the server component of IBM Tivoli Storage Manager FastBack software versions 5.5.x and 6.x prior to 6.1.12.2. This vulnerability resides in the server-side processing logic and specifically affects the handling of crafted commands that are transmitted over the network. The flaw enables remote attackers to execute arbitrary code on the affected system without requiring authentication, making it particularly dangerous in enterprise environments where storage management systems are often accessible across network boundaries. The vulnerability operates at the application layer and leverages improper input validation mechanisms within the FastBack server implementation, creating a pathway for malicious command injection attacks that can lead to complete system compromise.
The technical exploitation of this buffer overflow occurs when the FastBack server receives a specially crafted command that exceeds the allocated buffer space in memory. This condition allows attackers to overwrite adjacent memory locations, potentially corrupting program execution flow and enabling code execution at the privilege level of the affected service. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, though it may also exhibit characteristics of heap-based buffer overflow depending on the specific implementation details of the command processing routines. The attack vector requires network connectivity to the FastBack server and can be executed remotely without any authentication credentials, which significantly increases the attack surface and potential impact. The flaw demonstrates a classic lack of proper bounds checking in input validation, a common weakness that has been documented across numerous security frameworks and standards.
The operational impact of CVE-2015-8520 extends beyond simple code execution to encompass complete system compromise and potential data breach scenarios. An attacker who successfully exploits this vulnerability can gain full administrative control over the FastBack server, potentially accessing sensitive backup data, modifying storage configurations, or using the compromised system as a pivot point for further attacks within the enterprise network. The vulnerability affects organizations that rely on IBM Tivoli Storage Manager FastBack for backup and recovery operations, which typically contain critical business data and system configurations. The implications are particularly severe because backup systems often contain comprehensive system snapshots and data that can be leveraged for advanced persistent threats or lateral movement within network environments. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation would allow attackers to execute arbitrary commands on the compromised system.
Organizations affected by this vulnerability should prioritize immediate remediation through the application of IBM's official security patches released as part of the 6.1.12.2 update. The patch addresses the underlying buffer overflow by implementing proper input validation and bounds checking mechanisms in the command processing routines. Network segmentation and access controls should be implemented to limit exposure of FastBack server components to untrusted networks, though this does not eliminate the risk entirely. Security monitoring should be enhanced to detect unusual command patterns or network traffic that might indicate exploitation attempts. The vulnerability demonstrates the importance of regular security updates and vulnerability management programs, as this flaw existed for an extended period without detection in many enterprise environments. System administrators should also consider implementing intrusion detection systems specifically configured to identify patterns associated with buffer overflow exploitation attempts against storage management systems.