CVE-2015-4931 in Tivoli Storage Manager Fastback
Summary
by MITRE
Stack-based buffer overflow in the server in IBM Tivoli Storage Manager FastBack 6.1 before 6.1.12.1 allows remote attackers to execute arbitrary code via a crafted packet, a different vulnerability than CVE-2015-4932, CVE-2015-4933, CVE-2015-4934, and CVE-2015-4935.
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Analysis
by VulDB Data Team • 06/07/2022
The vulnerability identified as CVE-2015-4931 represents a critical stack-based buffer overflow flaw within the server component of IBM Tivoli Storage Manager FastBack version 6.1 prior to 6.1.12.1. This vulnerability exists in the network protocol handling mechanism where the server fails to properly validate input data length before copying it into fixed-size stack buffers. The flaw enables remote attackers to craft malicious packets that trigger the buffer overflow condition, potentially leading to arbitrary code execution on the affected system. The vulnerability specifically affects the server-side processing of network communications, making it particularly dangerous in environments where the FastBack server accepts connections from untrusted networks or external systems.
The technical implementation of this vulnerability stems from improper input validation within the protocol parsing code that handles incoming network packets. When the server receives a crafted packet containing oversized data, the application fails to check whether the incoming data exceeds the allocated buffer size on the stack. This allows an attacker to overwrite adjacent stack memory locations including return addresses and control data, enabling the execution of malicious code with the privileges of the running service. The vulnerability is classified as a stack-based buffer overflow under CWE-121, which specifically addresses buffer overflow conditions where data is written beyond the bounds of a stack buffer. This type of vulnerability is particularly dangerous because it can be exploited remotely without requiring authentication, making it a prime target for automated attacks.
The operational impact of CVE-2015-4931 extends beyond simple privilege escalation or denial of service scenarios. Successful exploitation can lead to complete system compromise, allowing attackers to establish persistent backdoors, exfiltrate sensitive data, or use the compromised system as a launch point for further attacks within the network infrastructure. Organizations using IBM Tivoli Storage Manager FastBack in production environments face significant risk exposure, particularly in scenarios where the server is accessible from the internet or connected to untrusted networks. The vulnerability's classification as a remote code execution flaw aligns with ATT&CK technique T1203, which covers exploitation of remote services, and T1059, which covers command and scripting interpreter usage. The attack surface is particularly wide given that FastBack servers often manage critical backup and recovery operations, making them attractive targets for cybercriminals seeking to disrupt business continuity or gain access to sensitive organizational data.
Organizations should prioritize immediate remediation through the installation of IBM's patch for FastBack version 6.1.12.1 or later, which addresses the buffer overflow condition through proper input validation and bounds checking. Network segmentation strategies should be implemented to limit direct access to FastBack servers from untrusted networks, while firewall rules should be configured to restrict communication to only necessary systems. Additionally, implementing intrusion detection systems and monitoring for suspicious network traffic patterns can help detect exploitation attempts. The vulnerability demonstrates the importance of regular security patch management and proper input validation practices in preventing remote code execution exploits. Security teams should also conduct thorough vulnerability assessments to identify any other instances of similar buffer overflow conditions within their IBM Tivoli Storage Manager installations and related systems, as the same architectural patterns may be present in other components of the broader software ecosystem.