CVE-2026-111913 in Admidio
Summary
by MITRE • 10/17/2026
Admidio from 5.0.0 before 5.0.16 contains an authorization bypass vulnerability that allows authenticated users to export lists despite export restrictions by requesting mode=pdfl. The groups_roles_export check in modules/groups-roles/lists_show.php omits pdfl, which later runs the pdf export, letting users with list view rights download member lists as PDF files.
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Analysis
by VulDB Data Team • 10/17/2026
The vulnerability identified within Admidio versions ranging from 5.0.0 to just before 5.0.16 represents a critical authorization bypass flaw that undermines the intended access control mechanisms of the application. This specific weakness allows authenticated users who possess only list view permissions to circumvent restrictions on data export functionality. By manipulating the request parameters, specifically by setting the mode parameter to pdfl, these users can trigger a PDF generation routine that was not properly gated by the same security checks applied to other export formats. The core of this issue lies in the modules/groups-roles/lists_show.php file, where the logic responsible for verifying whether a user is permitted to perform group and role exports fails to account for the pdfl mode. Consequently, while standard export functions are correctly restricted based on predefined roles and permissions, the PDF export path remains open to any authenticated individual with basic list viewing rights, effectively creating an unauthorized data exfiltration channel.
From a technical perspective, this flaw is classified as CWE-269, which denotes Improper Privilege Management. The application fails to enforce consistent authorization checks across different functional endpoints that perform similar actions. In secure software design, if multiple entry points lead to the same sensitive operation, such as exporting confidential member data, each endpoint must independently verify the user's privileges against a centralized or consistently applied policy matrix. Here, the developers implemented security controls for standard export modes but neglected to extend these checks to the PDF-specific mode parameter. This oversight results in an inconsistent state where the application’s security model is bypassed through parameter manipulation rather than exploiting a complex code execution flaw. The attacker does not need elevated privileges or administrative access; they only require the minimal level of authentication and list viewing rights that are typically granted to standard members, making this vulnerability particularly dangerous as it can be exploited by any user within the system.
The operational impact of this vulnerability is significant for organizations relying on Admidio for managing sensitive member information. Since the flaw allows users with low-level privileges to export complete lists in PDF format, it facilitates unauthorized data disclosure. This exported data often contains personally identifiable information (PII) such as names, contact details, and potentially other private attributes associated with group memberships or roles. The ability to generate these files means that an attacker can systematically harvest large volumes of sensitive data without detection by standard access logs if the logging mechanisms do not distinguish between authorized and unauthorized export attempts based on intent rather than just action type. This capability aligns closely with ATT&CK technique T1005, which describes Data from Local System Retrieval, as it involves an insider or compromised account extracting information directly from the application’s database via its own interface features. The ease of exploitation means that even non-technical users could potentially abuse this feature to leak organizational data for malicious purposes such as social engineering, phishing campaigns, or competitive intelligence gathering.
To mitigate this vulnerability and restore proper access control integrity, it is imperative to apply the official patch provided in Admidio version 5.0.16 or later, which addresses the missing authorization check in the specified module. For environments where immediate patching is not feasible due to operational constraints, a temporary workaround involves restricting web server-level access to the specific PHP files involved if possible, although this may impact legitimate functionality and is generally less effective than applying the vendor fix. Additionally, organizations should review their internal security policies regarding data export features in all content management systems they utilize. It is recommended to implement comprehensive logging that captures not just successful actions but also attempts to access restricted resources, allowing for better detection of such bypass attempts. Regular code reviews focusing on authorization logic across all similar endpoints can prevent recurrence of CWE-269 type issues by ensuring that privilege checks are uniformly applied regardless of the specific mode or format requested by the user.