CVE-2016-4866 in Cybozu Office
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the "Project" function in Cybozu Office 9.0.0 through 10.4.0.
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Analysis
by VulDB Data Team • 08/31/2020
The CVE-2016-4866 vulnerability represents a critical cross-site scripting flaw discovered in Cybozu Office versions 9.0.0 through 10.4.0, specifically within the "Project" function. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is one of the most prevalent and dangerous web application security flaws. The vulnerability stems from insufficient input validation and output encoding mechanisms within the project management functionality of the Cybozu Office suite, creating an exploitable condition where malicious users can inject arbitrary script code into web pages viewed by other users.
The technical implementation of this vulnerability occurs when the application fails to properly sanitize user-supplied input data within the Project function. When users create or modify project information, the application does not adequately filter or encode special characters that could be interpreted as executable script code by web browsers. This allows an attacker to submit malicious payloads through project-related fields such as project names, descriptions, or other editable content areas. The vulnerability is particularly concerning because it affects the core project management functionality, which is likely to be accessed by multiple users within an organization, amplifying the potential impact of successful exploitation.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, and data exfiltration. An attacker who successfully exploits this vulnerability can execute scripts in the context of a victim's browser session, potentially allowing them to steal authentication cookies, modify project data, or redirect users to malicious websites. The attack vector requires minimal privileges since the vulnerability exists in a function that is typically accessible to regular users within the organization, making it particularly dangerous in environments where multiple employees have access to project management features. This aligns with ATT&CK technique T1059.007 for Scripting and T1531 for Account Access Removal, as the vulnerability enables unauthorized access to user sessions and potential account compromise.
Organizations utilizing Cybozu Office versions within the affected range face significant security risks, as this vulnerability can be exploited by both external attackers and malicious insiders. The vulnerability's persistence in multiple versions suggests that it was not properly addressed in the application's input validation mechanisms, indicating a systemic security weakness in the software's data handling processes. Mitigation strategies should include immediate application of vendor patches, implementation of web application firewalls, and comprehensive input validation measures. Security teams should also consider conducting thorough penetration testing to identify any additional instances of similar vulnerabilities within the application's codebase, as this flaw demonstrates inadequate security controls in the software's core functionality. The vulnerability highlights the importance of proper output encoding and input sanitization practices, which are fundamental requirements for secure web application development and align with OWASP Top Ten security controls.