CVE-2016-2894 in Spectrum Protect
Summary
by MITRE
IBM Spectrum Protect (formerly Tivoli Storage Manager) 5.5 through 6.3 before 6.3.2.6, 6.4 before 6.4.3.3, and 7.1 before 7.1.6 allows local users to obtain sensitive retrieved data from arbitrary accounts in opportunistic circumstances by leveraging previous use of a symlink during archive and retrieve actions.
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Analysis
by VulDB Data Team • 08/26/2022
IBM Spectrum Protect represents a critical storage management solution that handles sensitive data across enterprise environments, making vulnerabilities within its architecture particularly concerning. The vulnerability described in CVE-2016-2894 stems from improper handling of symbolic links during archive and retrieve operations, creating a privilege escalation pathway that allows local users to access data from arbitrary accounts. This flaw exists in versions ranging from 5.5 through 6.3 before 6.3.2.6, 6.4 before 6.4.3.3, and 7.1 before 7.1.6, indicating a widespread issue affecting multiple major releases of the storage management platform. The vulnerability operates through opportunistic conditions where a malicious user can exploit the system's failure to properly validate symbolic link references during data retrieval processes, effectively bypassing normal access controls and account boundaries.
The technical implementation of this vulnerability involves the manipulation of symbolic link structures within the storage system's archive and retrieve mechanisms. When the system processes archive operations, it creates symbolic links that reference data stored in various locations, but fails to properly validate these references during subsequent retrieve operations. This validation gap allows a local attacker to create malicious symbolic links that point to sensitive data belonging to other accounts, enabling unauthorized data access through legitimate system operations. The flaw specifically manifests when the system does not properly resolve or sanitize symbolic link paths, allowing attackers to traverse the file system and access data that should be restricted to specific user accounts. This behavior aligns with CWE-367, which addresses Time-of-Check to Time-of-Use (TOCTOU) vulnerabilities where the system's state changes between validation and execution phases.
The operational impact of this vulnerability extends beyond simple data access, as it fundamentally compromises the integrity of the storage system's access control mechanisms. Local users who can leverage this vulnerability gain the ability to retrieve sensitive information from arbitrary accounts without proper authorization, potentially exposing confidential data such as backup files, system configurations, or user data. The opportunistic nature of the exploit means that successful attacks can occur when system administrators or legitimate users perform archive and retrieve operations, creating windows of opportunity for malicious actors. This vulnerability particularly affects enterprise environments where IBM Spectrum Protect is used for critical data backup and recovery operations, as it undermines the trust model that organizations rely upon for their data protection strategies. The attack vector combines elements of privilege escalation and data exfiltration, making it particularly dangerous for systems containing sensitive corporate or personal information.
Organizations should implement immediate mitigations including applying the vendor patches released for versions 6.3.2.6, 6.4.3.3, and 7.1.6, which address the symbolic link validation issues in the archive and retrieve functionality. System administrators should conduct thorough vulnerability assessments to identify any existing malicious symbolic links that could be exploited, particularly in areas where archive operations are performed. Network segmentation and access control measures should be enhanced to limit local user privileges and reduce the potential impact of successful exploitation attempts. The vulnerability demonstrates characteristics consistent with ATT&CK technique T1078 which covers valid accounts and privilege escalation through legitimate system access. Regular monitoring of archive and retrieve operations should be implemented to detect anomalous symbolic link creation patterns, and security awareness training should be provided to system administrators regarding the risks associated with improper file system handling during backup operations. Additionally, organizations should consider implementing automated tools to scan for and remediate vulnerable symbolic link configurations within their IBM Spectrum Protect environments, as the vulnerability can persist even after patching if malicious links were already established in the system.