Description

Incorrect Authorization vulnerability in Drupal Diff allows Forceful Browsing. This issue affects Diff versions: from 0.0.0 to 2.0.1, from 2.1.0 to 2.1.1.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.3",
  "pubDate": "2026-09-02T13:18:08.637Z",
  "pubdate": "2026-09-02T13:18:08.637Z",
  "executiveSummary": "The Drupal Diff module is susceptible to an Incorrect Authorization vulnerability, specifically facilitating Forceful Browsing attacks. This flaw arises from insufficient access control checks within the module's authorization logic, allowing unauthorized users to gain access to sensitive comparison data or resources that should be restricted based on permissions. The vulnerability impacts the Diff module across version ranges 0.0.0 to 2.0.1 and 2.1.0 to 2.1.1. The risk implication involves the potential exposure of sensitive content revisions or system data to unprivileged entities. Attackers capable of exploiting this vulnerability do not require elevated privileges, as the flaw bypasses intended access restrictions, enabling them to browse protected paths or perform actions for which they lack appropriate authorization. The primary impact is a breakdown of site integrity regarding data privacy and access control enforcement.",
  "technicalDetails": "The core of the vulnerability lies in an Incorrect Authorization implementation within the Drupal Diff module. In a secure environment, the module is expected to validate the user's permissions before rendering or providing access to comparison interfaces or historical version data. However, due to missing or flawed access control checks, the module fails to properly enforce these restrictions against direct requests.\nThe vulnerability manifests as a Forceful Browsing scenario. Forceful browsing occurs when an application exposes resources that are not properly protected by the authorization layer, allowing an attacker to access them by guessing or discovering the direct URL path. In this instance, because the Diff module does not verify the requester's identity or specific permission level before processing the request for diff generation or resource display, any user—including unauthenticated or low-privilege users—can navigate to these protected routes.\nThe exploitation process follows a predictable sequence: First, the attacker identifies the URL patterns used by the Diff module to present comparison views between different content revisions. Second, the attacker interacts directly with these endpoints without navigating through the standard user interface, which may have restricted access to the links. Third, the module, failing to invoke the necessary authorization API, proceeds to retrieve and display the requested information, which may include sensitive content that the user is not intended to view.\nThe vulnerable component resides in the routing and access control logic of the Drupal Diff module, which oversees the rendering of version differences. By failing to integrate with the Drupal access system effectively—such as missing 'access content' or specific module-level permission checks—the system treats unauthorized requests as valid. The affected versions (0.0.0 to 2.0.1 and 2.1.0 to 2.1.1) lack the necessary hardening to reject these crafted requests. The post-exploitation impact includes unauthorized information disclosure, where an attacker can systematically scrape versioned content, potentially revealing sensitive information that was previously removed or hidden from public view in newer revisions, thereby violating the confidentiality and integrity policies of the affected Drupal installation."
}