CVE-2017-2115 in Office
Summary
by MITRE
Cybozu Office 10.0.0 to 10.5.0 allows remote authenticated attackers to bypass access restriction to obtain "customapp" information via unspecified vectors.
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Analysis
by VulDB Data Team • 12/22/2020
The vulnerability identified as CVE-2017-2115 affects Cybozu Office versions 10.0.0 through 10.5.0, representing a critical access control flaw that enables remote authenticated attackers to bypass security restrictions and obtain sensitive custom application information. This vulnerability resides within the application's authorization mechanisms, specifically targeting the protection of customapp data that typically contains proprietary business logic, configuration parameters, and potentially sensitive operational details. The flaw manifests when authenticated users attempt to access restricted resources without proper validation of their privileges, creating a pathway for unauthorized information disclosure.
The technical nature of this vulnerability stems from insufficient input validation and access control checks within the Cybozu Office application framework. Attackers exploiting this weakness can leverage their authenticated status to make requests that should be restricted to authorized personnel only, thereby gaining access to custom application metadata and potentially sensitive operational data. This represents a classic privilege escalation scenario where legitimate users can access resources beyond their designated permissions. The unspecified vectors suggest that the vulnerability may be triggered through multiple attack paths including but not limited to API calls, web interface interactions, or direct protocol manipulation, making the attack surface broader and more difficult to predict.
The operational impact of this vulnerability extends beyond simple information disclosure, as custom application information often contains critical business logic, integration points, and system configurations that could be exploited for further attacks. An attacker who successfully exploits this vulnerability could potentially gain insights into the organization's internal systems, identify potential integration points with other services, or discover sensitive configuration details that could be used in subsequent phases of an attack. The implications are particularly severe for organizations using Cybozu Office for business process automation, as custom applications often contain proprietary workflows and business-critical data that could be leveraged for competitive advantage or financial gain.
Organizations affected by this vulnerability should immediately implement mitigation strategies including applying the vendor-provided patches, reviewing access control policies, and conducting comprehensive security assessments of their Cybozu Office deployments. The vulnerability aligns with CWE-284 which describes improper access control, and could potentially be leveraged in accordance with ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting. Security teams should also consider implementing network segmentation, monitoring for unusual access patterns, and conducting regular vulnerability assessments to prevent similar issues from arising in other components of their IT infrastructure. Given the nature of the flaw, organizations should also review their incident response procedures to ensure they can quickly detect and respond to unauthorized access attempts targeting custom application data.