CVE-2017-9340 in ownCloud Server
Summary
by MITRE
An attacker is logged in as a normal user and can somehow make admin to delete shared folders in ownCloud Server before 10.0.2.
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Analysis
by VulDB Data Team • 10/27/2019
The vulnerability described in CVE-2017-9340 represents a critical access control flaw within ownCloud Server versions prior to 10.0.2. This issue enables a low-privilege user to manipulate the system in such a way that an administrator is tricked into deleting shared folders that belong to the normal user. The flaw exists within the permission handling mechanisms of the cloud storage platform, specifically in how shared folder deletion operations are validated and executed. The vulnerability allows for privilege escalation through social engineering or manipulation techniques that exploit the trust relationship between users and administrators.
The technical implementation of this vulnerability stems from inadequate input validation and insufficient access control checks within the ownCloud server's folder management subsystem. When a normal user creates shared folders, the system fails to properly enforce ownership boundaries during deletion operations. This weakness can be exploited through crafted requests or manipulated user interactions that cause the administrative interface to process deletion commands for folders that should remain protected under normal access controls. The vulnerability manifests when the system does not properly verify that the user attempting to delete a shared folder has appropriate authorization rights, particularly when the folder was originally shared by a different user account.
The operational impact of this vulnerability extends beyond simple data loss scenarios, as it represents a fundamental breakdown in the security model of the cloud storage platform. An attacker with minimal privileges can potentially cause significant disruption to legitimate users' data access and collaboration workflows. The ability to manipulate an administrator into deleting shared folders creates a scenario where user data can be permanently removed without proper authorization, potentially affecting business continuity and user trust in the system. This vulnerability also undermines the integrity of shared resource management and can lead to unauthorized data exposure or loss of collaborative work environments.
Organizations using affected ownCloud Server versions should immediately implement mitigations including upgrading to version 10.0.2 or later, which contains the necessary patches to address the access control flaw. Additional protective measures should include implementing strict monitoring of deletion operations, particularly for shared folders, and establishing clear user access policies that limit the scope of operations that can be performed on shared resources. Security teams should also consider implementing network segmentation and access controls to prevent unauthorized access to administrative functions. This vulnerability aligns with CWE-284 which addresses improper access control issues, and represents a potential pathway for techniques described in the ATT&CK framework under privilege escalation and data manipulation categories, specifically targeting the persistence and privilege escalation tactics that attackers use to gain unauthorized access to sensitive resources within cloud environments.