CVE-2025-13985: Drupal Entity Share Auth Bypass Flaw

CVE-2025-13985 Overview

An Incorrect Authorization vulnerability has been identified in the Drupal Entity Share module that enables Forceful Browsing attacks. This flaw allows unauthorized users to access resources by manipulating URLs or parameters to bypass authorization controls, potentially exposing sensitive content that should be restricted.

Critical Impact
Attackers can bypass authorization controls to access restricted content through forceful browsing techniques, leading to unauthorized information disclosure.

Affected Products

Drupal Entity Share versions from 0.0.0 before 3.13.0

Discovery Timeline

2026-01-28 - CVE CVE-2025-13985 published to NVD
2026-01-29 - Last updated in NVD database

Technical Details for CVE-2025-13985

Vulnerability Analysis

This vulnerability falls under CWE-863 (Incorrect Authorization), a category of security flaws where an application fails to properly verify that a user has the necessary permissions to access a resource or perform an action. In the context of the Drupal Entity Share module, the authorization mechanism does not adequately validate access requests, enabling attackers to directly browse to resources that should be protected.

The Entity Share module is designed to facilitate content sharing between Drupal instances. When authorization checks are improperly implemented, users can enumerate or directly access shared entities without proper authentication or role-based access verification. This is particularly concerning in multi-site Drupal deployments where content syndication relies on robust access controls.

The network-accessible nature of this vulnerability means that remote attackers can exploit it without requiring any privileges or user interaction, though the impact is limited to unauthorized read access to potentially sensitive information.

Root Cause

The root cause of this vulnerability lies in insufficient authorization validation within the Entity Share module's access control logic. When processing requests for shared entities, the module fails to properly verify whether the requesting user has the appropriate permissions to access the requested content. This allows attackers to craft requests that bypass intended access restrictions.

Attack Vector

The attack vector for this vulnerability is network-based forceful browsing. An attacker can exploit this flaw by:

Identifying endpoints exposed by the Entity Share module
Constructing direct URL requests to access shared entity resources
Bypassing the intended authorization flow by directly requesting protected resources
Enumerating available entities through predictable URL patterns

The vulnerability requires no authentication, no user interaction, and has low attack complexity, making it straightforward for remote attackers to exploit. However, the scope is unchanged from the vulnerable component, and the impact is limited to confidentiality with no integrity or availability implications.

For detailed technical information, refer to the Drupal Security Advisory.

Detection Methods for CVE-2025-13985

Indicators of Compromise

Unusual access patterns to Entity Share module endpoints from unauthenticated sessions
Increased HTTP requests to entity sharing URLs with sequential or enumerated identifiers
Access log entries showing direct requests to shared entity resources without prior authentication
Failed authorization attempts followed by successful access to restricted content

Detection Strategies

Monitor web server access logs for requests to /entity-share/ or similar Entity Share module paths from unauthenticated users
Implement web application firewall (WAF) rules to detect and alert on forceful browsing patterns
Enable Drupal's watchdog logging and monitor for authorization bypass events
Configure intrusion detection systems to identify sequential resource enumeration attempts

Monitoring Recommendations

Enable verbose logging for the Entity Share module to capture all access attempts
Set up alerts for anomalous access patterns to shared entity endpoints
Monitor for bulk data access attempts that could indicate entity enumeration
Review authentication and authorization logs regularly for suspicious activity

How to Mitigate CVE-2025-13985

Immediate Actions Required

Upgrade Drupal Entity Share module to version 3.13.0 or later immediately
Audit existing Entity Share configurations for overly permissive access settings
Review access logs to determine if the vulnerability has been exploited
Temporarily disable the Entity Share module if immediate patching is not possible

Patch Information

The vulnerability is addressed in Entity Share version 3.13.0. Site administrators should update to this version or later to remediate the incorrect authorization issue. The patch implements proper authorization checks to prevent forceful browsing attacks.

For official patch details and download, see the Drupal Security Advisory.

Workarounds

Restrict access to Entity Share endpoints at the web server level using IP whitelisting
Implement additional authentication layers through reverse proxy configuration
Configure firewall rules to limit access to Entity Share functionality to trusted networks only
Disable anonymous access to the Entity Share module until patching is complete

bash

# Example: Apache .htaccess configuration to restrict Entity Share access
<LocationMatch "^/entity-share">
    Require ip 192.168.1.0/24
    Require ip 10.0.0.0/8
</LocationMatch>