CVE-2016-4867 in Cybozu Office
Summary
by MITRE
The "Project" function in Cybozu 9.0.0 through 10.4.0 allows remote authenticated users to read closed project information.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 08/31/2020
The vulnerability identified as CVE-2016-4867 resides within the Cybozu collaboration platform version 9.0.0 through 10.4.0, specifically affecting the "Project" function's access control mechanisms. This issue represents a significant information disclosure flaw that undermines the platform's security model by allowing authenticated users to bypass normal access restrictions and retrieve closed project data that should remain confidential. The vulnerability occurs at the application logic level where the system fails to properly validate user permissions when accessing project resources, creating a path for unauthorized data retrieval through legitimate authentication channels.
The technical implementation of this vulnerability stems from inadequate authorization checks within the project management functionality. When users attempt to access project information through the Project function, the system does not sufficiently verify whether the requesting user has appropriate clearance levels to view closed projects. This flaw typically manifests as a lack of proper access control enforcement during data retrieval operations, where the application fails to cross-reference user roles, project status flags, or security permissions against the requested resource. The vulnerability is particularly concerning because it operates within the context of authenticated users, meaning that an attacker who has obtained valid credentials can exploit this weakness without requiring additional privileged access or complex attack vectors.
From an operational impact perspective, this vulnerability creates substantial risk for organizations relying on Cybozu for project management and collaboration. Closed projects often contain sensitive business information, strategic plans, financial data, or proprietary content that should remain restricted to authorized personnel only. The ability for authenticated users to access this information undermines the integrity of the organization's data protection policies and could lead to competitive disadvantages, regulatory compliance violations, or even corporate espionage scenarios. Security incidents resulting from this vulnerability could trigger extensive forensic investigations, regulatory penalties, and damage to organizational reputation while potentially exposing intellectual property to unauthorized parties.
The vulnerability aligns with CWE-285, which addresses insufficient authorization issues in software systems, and demonstrates characteristics consistent with ATT&CK technique T1078.004 for valid accounts, where attackers leverage legitimate credentials to access restricted resources. Organizations should implement immediate mitigations including updating to patched versions of Cybozu software, reviewing and strengthening access control policies, and conducting comprehensive security audits of project management functionalities. Additional defensive measures include implementing network segmentation, monitoring access patterns for unusual data retrieval activities, and establishing strict role-based access controls that prevent users from accessing project information beyond their designated clearance levels. Regular security assessments and penetration testing should be conducted to identify similar authorization flaws in other application components and ensure comprehensive protection against privilege escalation attacks.