CVE-2016-4872 in Cybozu Office
Summary
by MITRE
The "breadcrumb trail" component in Cybozu Office 9.0.0 through 10.4.0 allows remote authenticated users to read the names of closed projects.
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Analysis
by VulDB Data Team • 08/31/2020
The vulnerability identified as CVE-2016-4872 resides within the breadcrumb trail functionality of Cybozu Office versions 9.0.0 through 10.4.0, representing a significant information disclosure flaw that affects remote authenticated users. This issue stems from inadequate access control mechanisms within the software's navigation component, where the breadcrumb trail fails to properly enforce project visibility restrictions. The flaw allows attackers who have authenticated access to the system to enumerate and discover the names of projects that have been closed or otherwise restricted from normal viewing access. This represents a direct violation of the principle of least privilege and demonstrates a failure in the software's authorization model.
The technical implementation of this vulnerability involves the breadcrumb trail component maintaining and displaying project references without proper validation of user permissions for each project in the navigation path. When users navigate through the application, the breadcrumb trail component retrieves project information from backend systems and displays it in the user interface without filtering based on the authenticated user's access rights. This creates a scenario where even closed projects that should be invisible to regular users are exposed through the navigation component. The vulnerability is classified under CWE-200, Information Disclosure, and more specifically relates to CWE-668, which addresses insufficient protection of data in the application. This type of flaw enables attackers to gather intelligence about the system's project structure and potentially identify sensitive information about closed projects that may contain confidential data or business-critical information.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with a method to map the project landscape of the organization. An attacker with valid credentials can systematically enumerate closed projects to identify potential targets for further attacks, understand organizational structure, and discover projects that may contain sensitive data or vulnerabilities. This reconnaissance capability can significantly aid in planning more sophisticated attacks, as the attacker gains knowledge about the organization's project portfolio and potentially identifies projects with weaker security controls or higher value data. The vulnerability also undermines the security model of Cybozu Office, as it allows unauthorized access to information that should remain protected within the system's access control framework.
Organizations utilizing affected versions of Cybozu Office should immediately implement mitigations including applying the vendor-provided security patches and updates that address the access control flaw in the breadcrumb trail component. Network segmentation and monitoring should be enhanced to detect unusual enumeration patterns that may indicate attempts to exploit this vulnerability. Additionally, administrators should review and tighten access controls for project visibility settings, ensuring that project names and metadata are properly restricted based on user permissions. The vulnerability demonstrates the importance of comprehensive access control testing, particularly for navigation and user interface components that may inadvertently expose system information. This issue aligns with ATT&CK technique T1087.001, Account Discovery, and T1005, Data from Local System, as it enables unauthorized information gathering through legitimate application interfaces. Organizations should also consider implementing automated vulnerability scanning to identify similar access control flaws in other components of their application stack, as this type of information disclosure vulnerability can often be found in complex enterprise applications where multiple access control points exist.