CVE-2026-107311 in Permissions by Term Plugin
Summary
by MITRE • 10/30/2026
Improper Check for Unusual or Exceptional Conditions vulnerability in Drupal Permissions by Term allows Forceful Browsing. This issue affects Permissions by Term versions: from 0.0.0 to 3.1.41.
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Analysis
by VulDB Data Team • 10/30/2026
The vulnerability identified as Improper Check for Unusual or Exceptional Conditions within the Drupal module Permissions by Term represents a significant security flaw that enables unauthorized access through forceful browsing techniques. This issue specifically impacts versions of the module ranging from its initial release at version 0.0.0 up to and including version 3.1.41. The core of this vulnerability lies in the application's failure to adequately validate user inputs or session states when processing requests related to term-based permissions, allowing attackers to bypass intended access controls by directly manipulating URLs or request parameters that are not properly secured against direct object reference attacks.
From a technical perspective, the flaw stems from an insufficient verification mechanism within the module’s logic for determining whether a specific user has permission to view or interact with content associated with particular taxonomy terms. Instead of relying on robust server-side authorization checks that verify the current session's privileges against the requested resource, the application relies on assumptions about how users navigate the site. This oversight allows an authenticated attacker who possesses valid credentials but lacks explicit administrative rights for certain sections to enumerate and access restricted resources by systematically guessing or forcing URLs associated with protected taxonomy terms. The absence of strict checks for unusual conditions means that standard HTTP requests can be crafted to retrieve sensitive data without triggering appropriate denial responses, effectively turning the application into a source of information leakage through direct object reference exploitation.
The operational impact of this vulnerability is substantial, particularly in environments where content confidentiality and role-based access control are critical. Attackers can exploit this weakness to perform forceful browsing, which involves iteratively requesting different resource identifiers until they find accessible ones that should be restricted. This capability facilitates unauthorized data exposure, potentially revealing sensitive business information, user details, or proprietary content stored within the Drupal site. Furthermore, because the vulnerability affects a wide range of versions starting from zero, legacy systems and those with delayed update cycles are particularly at risk. The ability to bypass permission checks undermines the integrity of the access control model, leading to potential compliance violations in industries governed by strict data protection regulations such as GDPR or HIPAA, where unauthorized disclosure of protected information carries severe legal and financial consequences.
In alignment with industry standards, this vulnerability is best classified under CWE-284 Improper Access Control, specifically relating to insufficient authorization checks that allow users to access resources they are not permitted to view. It also maps closely to the Common Weakness Enumeration entry for Direct Object Reference (CWE-639), as it involves accessing objects directly by user-supplied input without proper validation of ownership or permissions. Within the MITRE ATT&CK framework, this behavior corresponds to techniques associated with Discovery and Collection phases, where adversaries use forceful browsing to map out accessible resources and gather intelligence on the target environment for further exploitation. The lack of exception handling for edge cases in permission logic also touches upon CWE-754 Improper Check for Unusual or Exceptional Conditions, highlighting a failure to anticipate malicious input patterns that deviate from normal usage flows.
To mitigate this vulnerability, organizations running affected versions of Permissions by Term must prioritize immediate patching to the latest stable release where these access control checks have been hardened. Administrators should verify their Drupal installation and ensure that all contributed modules are updated to address known security flaws. In addition to updating software, implementing a Web Application Firewall can provide an additional layer of defense by detecting and blocking patterns associated with forceful browsing or direct object reference attacks before they reach the application logic. It is also advisable to conduct regular code reviews focusing on authorization checks for all endpoints that handle taxonomy-related data, ensuring that every request validates both user identity and permission levels against the requested resource. Finally, enabling comprehensive logging and monitoring can help detect anomalous access patterns indicative of exploitation attempts, allowing security teams to respond swiftly to potential breaches while maintaining a robust defense-in-depth strategy.