CVE-2026-82879 in DataEase
Summary
by MITRE • 08/31/2026
DataEase before 2.10.26 contains multiple access control defects in the sharing link module. Tickets are not bound to the target share UUID, so a valid ticket issued for one share can be reused against another (ShareTicketManage.validateTicket / POST /de2api/share/proxyInfo). The POST /de2api/share/validate endpoint issues a LinkToken after password verification without requiring a ticket, bypassing the 'ticket mandatory' policy. Additionally, the ticket create and delete endpoints (POST /de2api/ticket/saveTicket, POST /de2api/ticket/delTicket) lack share-ownership checks, allowing an authenticated user who knows another user's ticket to modify, rebind, or delete it (denial of service), and GET /de2api/share/queryRelationByUserId/{uid} allows authenticated users to enumerate other users' share mappings.
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Analysis
by VulDB Data Team • 08/31/2026
The vulnerability in DataEase versions prior to 2.10.26 represents a critical failure in access control mechanisms within the sharing link module, fundamentally undermining the integrity and confidentiality of shared resources. The core technical flaw stems from an improper binding between authentication tickets and their intended target share UUIDs. In a secure implementation, a ticket issued for accessing a specific resource should be cryptographically or logically bound to that unique identifier, ensuring it cannot be repurposed. However, in this affected version, the validation logic within ShareTicketManage.validateTicket fails to enforce this binding strictly. Consequently, an attacker who obtains a valid authentication ticket intended for one shared item can reuse that same token to access completely different shares, effectively bypassing granular permission controls and gaining unauthorized access to data they were not originally granted rights to view.
Beyond the issue of ticket reusability, there is a significant policy enforcement failure regarding link tokens. The endpoint POST /de2api/share/validate is designed to issue LinkTokens after password verification, yet it operates without requiring a valid share ticket as mandated by security policies. This omission allows an attacker who knows or can guess a share identifier and its associated password to directly obtain a functional access token without undergoing the full authentication chain that includes ticket validation. This bypass effectively neutralizes the multi-layered defense strategy intended for shared links, reducing the barrier to entry for unauthorized data retrieval to merely knowledge of the link URL and password.
The vulnerability extends further into user interaction capabilities through insufficient ownership verification on ticket management endpoints. The API routes POST /de2api/ticket/saveTicket and POST /de2api/ticket/delTicket do not verify that the authenticated user making the request is the actual owner or authorized manager of the specific ticket being modified or deleted. This lack of authorization check allows any authenticated user who can discover another user's ticket identifier to perform destructive actions such as rebinding, modifying, or deleting those tickets. From an operational impact perspective, this enables a denial-of-service attack against other users by invalidating their active sessions or preventing them from accessing shared resources they legitimately own. It also facilitates potential privilege escalation if the rebind functionality allows redirecting access rights to attacker-controlled entities.
Furthermore, the system exposes sensitive internal mapping information through the endpoint GET /de2api/share/queryRelationByUserId/{uid}. This API allows authenticated users to enumerate share mappings associated with other user IDs without sufficient authorization checks. This capability facilitates reconnaissance activities where an attacker can map out which resources are shared by specific individuals or groups within the organization. Such enumeration aids in planning more targeted attacks against high-value targets identified through this data leakage, as it reveals the structure of internal sharing and potentially exposes sensitive business documents that were intended for limited audiences only.
From a classification standpoint, these issues align with CWE-269 Improper Privilege Escalation due to the ability to reuse tickets across different contexts and modify others' resources. The failure to enforce proper access control on API endpoints corresponds directly to CWE-862 Missing Authorization, while the enumeration of user share mappings relates to CWE-200 Exposure of Sensitive Information Through Information Retrieval. In terms of offensive security frameworks like MITRE ATT&CK, these vulnerabilities facilitate techniques such as T1530 Data from Cloud Storage Object Discovery through the enumeration API and T1078 Valid Accounts for initial access via reused or bypassed tokens.
To mitigate these risks, immediate patching to version 2.10.26 or later is required to address the underlying code defects in the sharing module. Administrators should ensure that all ticket-related endpoints enforce strict ownership verification, ensuring that only the creator of a ticket can modify or delete it. The validation logic for share tickets must be updated to strictly bind each ticket to its specific target UUID and reject any attempts to use a token against an unrelated resource. Additionally, the POST /de2api/share/validate endpoint should be hardened to require a valid ticket in conjunction with password verification if that is part of the intended security policy. Finally, access controls on enumeration endpoints like queryRelationByUserId must be tightened to prevent authenticated users from querying share mappings for other user IDs unless explicitly authorized by role-based permissions.