CVE-2026-109203 in Community Edition
Summary
by MITRE • 10/12/2026
LogicalDOC Community Edition through 9.3 contains a missing authorization vulnerability in the ConvertPdf servlet that allows authenticated users to download restricted PDF documents. Attackers can enumerate sequential docId values and use the version parameter to retrieve any PDF and its versions from folders they cannot access.
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Analysis
by VulDB Data Team • 10/12/2026
The identified vulnerability represents a critical failure in server-side access control mechanisms within LogicalDOC Community Edition, specifically affecting versions up through 9.3. This flaw is categorized as an Insecure Direct Object Reference (IDOR), which corresponds to CWE-639 in the Common Weakness Enumeration taxonomy. The core issue resides in the ConvertPdf servlet, a component responsible for rendering or converting document formats into PDF files for user viewing. While the application correctly implements authentication and basic folder-level permissions, it fails to validate whether the authenticated user initiating the request possesses explicit read access rights to the specific resource identified by the docId parameter. This architectural oversight allows any logged-in user to bypass intended security boundaries simply by manipulating input parameters rather than exploiting a code execution or injection flaw.
The operational mechanics of this vulnerability rely on predictable identifier patterns and insufficient authorization checks during the conversion process. Attackers can exploit this by enumerating sequential document identifiers, commonly known as docId values, which are often generated using auto-incrementing integer sequences in database-backed content management systems. By systematically iterating through these IDs, an attacker can identify valid documents within the system regardless of their organizational structure or folder hierarchy. Furthermore, the vulnerability is exacerbated by the availability of a version parameter, which allows the requester to specify particular iterations of a document. This capability enables the retrieval not only of current restricted PDFs but also historical versions that may contain sensitive information previously thought to be secure or deleted from active views.
The impact of this weakness extends beyond simple data leakage; it fundamentally undermines the confidentiality guarantees provided by the content management system's permission model. Since authenticated users can download documents they are explicitly denied access to, confidential corporate records, legal contracts, personal identifiable information, and proprietary intellectual property become exposed to unauthorized parties within the network perimeter. This scenario aligns with several techniques in the MITRE ATT&CK framework, particularly T1078 Valid Accounts for initial access persistence and T1530 Data from Local System or Network-Attached Storage for data exfiltration via non-standard channels. The ability to enumerate resources also facilitates further reconnaissance, allowing attackers to map out the organization's document structure and identify high-value targets based on file names or metadata visible in the response headers or content itself.
Mitigation strategies must address both immediate remediation and long-term architectural improvements. The most effective solution is for vendors to release a patch that enforces strict authorization checks within the ConvertPdf servlet, ensuring that every request validates the user's permissions against the specific docId before processing the conversion logic. In environments where patching is not immediately feasible, administrators should implement network-level controls such as Web Application Firewalls (WAF) rules that detect and block sequential enumeration patterns or unusual access frequencies to document endpoints. Additionally, transitioning from predictable integer-based identifiers to universally unique identifiers (UUIDs) can significantly increase the difficulty of resource enumeration for attackers. Regular security audits focusing on object reference validation across all API endpoints are essential to prevent similar logic flaws in other modules of the application.