CVE-2017-10857 in Office
Summary
by MITRE
Cybozu Office 10.0.0 to 10.6.1 allows authenticated attackers to bypass access restriction to perform arbitrary actions via "Cabinet" function.
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Analysis
by VulDB Data Team • 11/24/2019
The vulnerability identified as CVE-2017-10857 affects Cybozu Office versions 10.0.0 through 10.6.1, representing a critical access control flaw that enables authenticated attackers to circumvent security restrictions within the application. This issue specifically targets the Cabinet function, which serves as a file management component within the office suite. The vulnerability stems from insufficient input validation and improper access control mechanisms that fail to properly verify user permissions before executing sensitive operations. Attackers who have gained legitimate authentication credentials can exploit this weakness to perform unauthorized actions that should typically be restricted to authorized users only.
The technical implementation of this vulnerability involves a flaw in the permission checking logic within the Cabinet function's backend processing. When users interact with the file cabinet functionality, the application should verify that the authenticated user possesses the appropriate privileges to perform the requested operation. However, the flaw allows attackers to manipulate the request parameters or bypass the permission validation checks entirely. This type of vulnerability falls under CWE-284 which specifically addresses improper access control issues. The vulnerability can be exploited through crafted requests that manipulate the application's internal state or by leveraging the authenticated session to escalate privileges.
The operational impact of this vulnerability is significant as it provides attackers with the ability to perform arbitrary actions within the application's file management system. This could include accessing restricted files, modifying or deleting sensitive data, creating new files in protected directories, or even executing unauthorized administrative functions. The consequences extend beyond simple data exposure to potentially enable further attacks within the compromised environment, as attackers could use the elevated privileges to access additional system resources or establish persistent access. The vulnerability represents a serious breach of the principle of least privilege, where the application fails to properly enforce access controls that should prevent unauthorized operations.
Organizations utilizing affected Cybozu Office versions should implement immediate mitigations including applying the vendor-provided security patches, implementing network segmentation to limit access to the vulnerable application, and monitoring for suspicious activities related to the Cabinet function. Additional protective measures include strengthening authentication mechanisms, implementing proper session management, and conducting regular security assessments of the application's access control mechanisms. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and can be leveraged as part of a broader attack chain to establish persistent access or move laterally within the network. The vulnerability also highlights the importance of proper input validation and access control implementation in enterprise applications, aligning with defensive techniques that emphasize secure coding practices and regular vulnerability assessments to prevent similar issues in the future.