CVE-2026-81164 in Entity PDF Plugin
Summary
by MITRE • 09/02/2026
Missing Authorization vulnerability in Drupal Entity PDF allows Forceful Browsing. This issue affects Entity PDF versions: from 0.0.0 to 2.1.5.
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Analysis
by VulDB Data Team • 09/02/2026
The Entity PDF module for the Drupal content management system contains a critical access control flaw that permits unauthorized users to force browse and download protected documents. This vulnerability arises because the module fails to properly enforce authorization checks when handling requests for PDF files generated or stored through its functionality. In a secure implementation, any request to retrieve sensitive data must be validated against the current user's permissions before granting access. However, in versions ranging from 0.0.0 up to and including 2.1.5, this validation step is either missing or incorrectly implemented, allowing attackers to bypass authentication mechanisms entirely by directly accessing file paths or endpoints associated with PDF generation.
From a technical perspective, the flaw represents a classic case of broken access control where the server relies on security through obscurity rather than explicit permission verification. Attackers can exploit this by manipulating URL parameters or constructing direct requests to internal API routes that serve PDF content. Since the module does not verify whether the requesting user has the necessary permissions to view specific entities or files, any individual with knowledge of the file structure or endpoint URLs can retrieve documents intended for authorized personnel only. This lack of server-side validation is particularly dangerous in environments where sensitive business information, personal data, or confidential reports are managed through Drupal and served via this module.
The operational impact of this vulnerability is significant, as it leads to a complete compromise of confidentiality for any PDF content handled by the affected modules. Unauthorized access can result in the leakage of proprietary intellectual property, customer personally identifiable information, financial records, or other regulated data depending on the organization's usage patterns. Beyond immediate data exposure, such vulnerabilities often serve as an initial foothold for more complex attacks, including further enumeration of site structure and potential integration with other exploits to escalate privileges within the application environment. The ease of exploitation means that automated scanning tools can rapidly identify vulnerable instances across the internet, increasing the risk of widespread compromise without targeted effort from adversaries.
This issue aligns closely with CWE-284 Improper Access Control and is categorized under MITRE ATT&CK technique T1078 Valid Accounts if combined with credential theft, though in this specific instance it primarily reflects direct unauthorized access akin to T1530 Data from Local System or general data exfiltration via improper authorization checks. The absence of proper role-based access control enforcement allows any user, including anonymous visitors, to interact with resources they should not be able to reach. This violates the fundamental security principle that access rights must be explicitly granted and verified for every action performed on protected assets.
To mitigate this vulnerability, organizations running Drupal sites with Entity PDF versions prior to 2.1.6 must upgrade immediately to a patched version where proper authorization checks have been implemented. Until an update is applied, administrators should consider implementing web application firewall rules that restrict access to known vulnerable endpoints or disable the module if it is not strictly required for business operations. Additionally, reviewing server configurations to ensure that direct file path access is blocked can provide a temporary layer of defense against forceful browsing attempts. Regular security audits and penetration testing are recommended to identify similar misconfigurations in other modules and ensure comprehensive protection of sensitive data assets within the Drupal ecosystem.