CVE-2016-4908 in Garoon
Summary
by MITRE
Cybozu Garoon 3.0.0 to 4.2.2 allows remote authenticated attackers to bypass access restriction to alter or delete another user's private RSS settings via unspecified vectors.
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Analysis
by VulDB Data Team • 12/26/2020
The vulnerability identified as CVE-2016-4908 affects Cybozu Garoon versions 3.0.0 through 4.2.2, representing a critical access control flaw that undermines the security model of the application. This issue enables authenticated attackers to circumvent intended access restrictions and manipulate private RSS settings belonging to other users within the system. The vulnerability stems from insufficient input validation and authorization checks within the application's privilege management mechanisms, allowing malicious actors with legitimate user credentials to exploit the system's trust model and gain unauthorized access to sensitive user data.
The technical implementation of this vulnerability involves the exploitation of improper access control validation during RSS setting modifications. When users attempt to alter their RSS configurations, the application fails to properly verify whether the requesting user has legitimate authorization to modify another user's settings. This weakness creates a path for privilege escalation where authenticated users can manipulate system resources beyond their intended scope. The unspecified vectors suggest that the flaw may be present across multiple API endpoints or interface components, making the attack surface more expansive and difficult to predict. This type of vulnerability typically falls under the CWE-285 category of Improper Authorization, which specifically addresses situations where systems fail to properly enforce access controls.
The operational impact of CVE-2016-4908 extends beyond simple data manipulation, as it compromises the fundamental security principles of user privacy and data integrity within the Garoon environment. Attackers can potentially disrupt communication flows by modifying RSS feeds that other users rely upon, delete critical configuration data, or even inject malicious content that could propagate through the system. The ability to alter private settings affects not only individual user experience but also organizational workflows that depend on accurate RSS feed integration for information dissemination. This vulnerability directly impacts the confidentiality, integrity, and availability aspects of the CIA triad, as it allows unauthorized modifications to user-specific data while potentially exposing the system to further exploitation vectors. Organizations using affected versions of Garoon may experience data breaches, service disruptions, and potential compliance violations depending on their regulatory requirements.
Mitigation strategies for this vulnerability require immediate implementation of proper access control validation mechanisms throughout the application's codebase. System administrators should prioritize updating to patched versions of Cybozu Garoon as soon as possible, while also implementing additional monitoring measures to detect unauthorized access attempts. The fix typically involves strengthening authentication checks during RSS setting modifications to ensure that users can only access and modify their own configuration data. Security teams should conduct thorough code reviews focusing on authorization logic and implement proper input sanitization to prevent exploitation of similar vulnerabilities. Organizations may also consider implementing network-level controls such as firewalls and intrusion detection systems to monitor for suspicious activity patterns that could indicate exploitation attempts. This vulnerability aligns with ATT&CK technique T1078 for Valid Accounts and T1566 for Phishing, as it demonstrates how legitimate user credentials can be leveraged to bypass security controls and access restricted resources.