CVE-2025-41342: Canaldenuncia.app Auth Bypass Vulnerability

CVE-2025-41342 Overview

A lack of authorization vulnerability has been discovered in CanalDenuncia.app, a whistleblowing platform application. This vulnerability allows an unauthenticated attacker to access other users' information by sending a crafted POST request through the id_user parameter in the /backend/api/buscarUsuarioId.php endpoint. The flaw represents a classic Insecure Direct Object Reference (IDOR) pattern where the application fails to verify whether the requesting user has permission to access the requested user data.

Critical Impact

Unauthorized access to sensitive user information is possible without authentication, potentially exposing personal data of whistleblowers and compromising the confidentiality of the reporting platform.

Affected Products

• CanalDenuncia CanalDenuncia.app (all versions)

Discovery Timeline

• November 4, 2025 - CVE-2025-41342 published to NVD
• November 5, 2025 - Last updated in NVD database

Technical Details for CVE-2025-41342

Vulnerability Analysis

This vulnerability stems from Missing Authorization (CWE-862) in the CanalDenuncia.app backend API. The affected endpoint /backend/api/buscarUsuarioId.php processes user lookup requests but fails to implement proper authorization checks before returning user data. An attacker can enumerate user IDs and retrieve sensitive information belonging to any user in the system without being authenticated or authorized to access that data.

The network-accessible nature of this vulnerability means it can be exploited remotely without any special conditions or user interaction. This is particularly concerning for a whistleblowing application where user anonymity and data confidentiality are paramount to the platform's purpose.

Root Cause

The root cause is the absence of authorization logic in the buscarUsuarioId.php API endpoint. When the backend receives a POST request with an id_user parameter, it directly queries the database and returns the associated user information without verifying:

1. Whether the requester is authenticated
2. Whether the authenticated user has permission to access the requested user's data
3. Whether any rate limiting or access controls are in place

This represents a fundamental authorization bypass where the application trusts user-supplied input (id_user) without validating access rights.

Attack Vector

The attack can be executed by sending direct POST requests to the vulnerable endpoint with arbitrary user ID values. An attacker would:

1. Identify the vulnerable API endpoint at /backend/api/buscarUsuarioId.php
2. Craft POST requests with different id_user parameter values
3. Enumerate through user IDs to extract information about all users in the system
4. Collect sensitive user data without authentication

The vulnerability is exploited through simple HTTP POST requests targeting the backend API. An attacker can manipulate the id_user parameter to access arbitrary user records. For detailed technical information, refer to the INCIBE Security Notice.

Detection Methods for CVE-2025-41342

Indicators of Compromise

• Unusual volume of POST requests to /backend/api/buscarUsuarioId.php from single IP addresses
• Sequential or enumerated values in id_user parameters indicating automated scanning
• Access patterns showing requests for multiple user IDs from unauthenticated sessions
• Anomalous API response sizes indicating bulk data retrieval

Detection Strategies

• Implement API logging and monitor for enumeration patterns against user-related endpoints
• Deploy Web Application Firewall (WAF) rules to detect and block parameter tampering attempts
• Configure intrusion detection systems to alert on suspicious POST request patterns to backend API endpoints
• Review access logs for requests to buscarUsuarioId.php that lack proper authentication tokens

Monitoring Recommendations

• Enable detailed logging on the /backend/api/ directory to capture all requests with parameters
• Set up alerts for high-frequency requests to user lookup endpoints from single sources
• Monitor for failed authentication attempts followed by direct API endpoint access
• Implement real-time dashboards tracking API endpoint access patterns

How to Mitigate CVE-2025-41342

Immediate Actions Required

• Restrict access to the /backend/api/buscarUsuarioId.php endpoint pending a security patch
• Implement authentication requirements for all API endpoints as an interim measure
• Review server logs to identify any potential exploitation attempts
• Consider temporarily disabling the vulnerable endpoint if not critical to operations

Patch Information

Consult the vendor CanalDenuncia for official patch information. Review the INCIBE Security Notice for the latest security guidance and remediation details.

Workarounds

• Implement server-side authorization checks to validate that the requesting user has permission to access the requested user data
• Add authentication middleware to protect the vulnerable API endpoint
• Deploy network-level access controls to limit API access to trusted sources only
• Implement rate limiting on user lookup endpoints to slow enumeration attacks

# Example Apache .htaccess configuration to restrict access
<Files "buscarUsuarioId.php">
    # Require authentication for this endpoint
    AuthType Basic
    AuthName "Restricted API Access"
    AuthUserFile /path/to/.htpasswd
    Require valid-user
    
    # Additional IP-based restrictions
    Order deny,allow
    Deny from all
    Allow from 192.168.1.0/24
</Files>