CVE-2025-41111: Canaldenuncia.app Auth Bypass Vulnerability

CVE-2025-41111 Overview

A lack of authorization vulnerability has been detected in CanalDenuncia.app. This vulnerability allows an attacker to access other users' information by sending a POST request through the parameter id_denuncia in /backend/api/buscarComentariosByDenuncia.php. The flaw is classified as CWE-862 (Missing Authorization), indicating that the application fails to properly verify whether a user is authorized to access the requested resource before returning sensitive data.

Critical Impact

Unauthorized attackers can access confidential user complaint data and comments by manipulating the id_denuncia parameter, leading to significant privacy violations and potential exposure of sensitive whistleblower information.

Affected Products

• CanalDenuncia CanalDenuncia.app (all versions)

Discovery Timeline

• 2025-11-04 - CVE-2025-41111 published to NVD
• 2025-11-05 - Last updated in NVD database

Technical Details for CVE-2025-41111

Vulnerability Analysis

This vulnerability stems from a missing authorization check in the CanalDenuncia.app backend API. The affected endpoint /backend/api/buscarComentariosByDenuncia.php processes POST requests containing an id_denuncia parameter to retrieve comments associated with a specific complaint (denuncia). However, the application fails to verify whether the requesting user has the appropriate permissions to access the complaint data before returning the associated comments.

CanalDenuncia.app is a whistleblowing and complaint management platform, making this vulnerability particularly concerning as it could expose sensitive information submitted by individuals reporting misconduct or illegal activities. The network-accessible nature of this vulnerability means any remote attacker can exploit it without requiring prior authentication.

Root Cause

The root cause is CWE-862: Missing Authorization. The vulnerable PHP endpoint does not implement proper access control checks before processing the id_denuncia parameter. When a request is received, the application directly queries the database for comments matching the provided complaint ID without first validating that the requesting user has legitimate access rights to that specific complaint record.

This represents a classic Insecure Direct Object Reference (IDOR) pattern where user-supplied input directly references database objects without proper authorization validation.

Attack Vector

The attack is network-based and requires no authentication or user interaction. An attacker can exploit this vulnerability by sending crafted POST requests to the vulnerable endpoint with sequential or enumerated id_denuncia values.

The exploitation process involves:

1. Identifying the vulnerable endpoint at /backend/api/buscarComentariosByDenuncia.php
2. Crafting a POST request with arbitrary id_denuncia values
3. Iterating through complaint IDs to harvest comments and associated user information
4. Collecting sensitive data from multiple user complaints

Since no authentication is required and the attack complexity is low, an attacker can easily automate this process to extract large volumes of confidential complaint data.

Detection Methods for CVE-2025-41111

Indicators of Compromise

• Unusual volume of POST requests to /backend/api/buscarComentariosByDenuncia.php from a single source
• Sequential or pattern-based id_denuncia parameter values in request logs suggesting enumeration attempts
• Access to complaint records from IP addresses not associated with authorized users
• Abnormal API response sizes indicating bulk data extraction

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block parameter enumeration attempts
• Monitor application logs for repeated requests to the vulnerable endpoint with varying id_denuncia values
• Deploy anomaly detection to identify access patterns inconsistent with normal user behavior
• Review access logs for requests accessing complaint data without corresponding authenticated sessions

Monitoring Recommendations

• Enable detailed logging on the /backend/api/buscarComentariosByDenuncia.php endpoint including source IP, timestamps, and parameter values
• Set up alerts for high-frequency API requests to complaint-related endpoints
• Monitor for unauthorized data access patterns using SIEM correlation rules
• Implement rate limiting on sensitive API endpoints to slow enumeration attacks

How to Mitigate CVE-2025-41111

Immediate Actions Required

• Review and restrict access to the /backend/api/buscarComentariosByDenuncia.php endpoint immediately
• Implement server-side authorization checks to validate user permissions before returning complaint data
• Audit access logs to identify any potential exploitation that may have already occurred
• Consider temporarily disabling the vulnerable endpoint if authorization controls cannot be implemented quickly

Patch Information

Consult the INCIBE Security Notice for official vendor guidance on available patches and remediation steps.

Organizations should contact the CanalDenuncia vendor directly for specific patch availability and apply updates as soon as they become available. Until a patch is released, implement the recommended workarounds below.

Workarounds

• Implement authentication requirements on all API endpoints handling sensitive complaint data
• Add server-side session validation to verify user identity before processing requests
• Implement authorization checks that validate the requesting user's relationship to the complaint being accessed
• Deploy a web application firewall (WAF) with rules to detect and block IDOR/enumeration attacks
• Apply network-level access restrictions to limit API access to trusted sources only

# Example Apache configuration to restrict access to the vulnerable endpoint
<Location "/backend/api/buscarComentariosByDenuncia.php">
    # Require authentication for this endpoint
    AuthType Basic
    AuthName "Restricted Access"
    AuthUserFile /etc/apache2/.htpasswd
    Require valid-user
    
    # Rate limiting (requires mod_ratelimit)
    SetOutputFilter RATE_LIMIT
    SetEnv rate-limit 100
</Location>