CVE-2025-41113: Canaldenuncia.app Auth Bypass Flaw

CVE-2025-41113 Overview

A lack of authorization vulnerability has been detected in CanalDenuncia.app, a whistleblowing and complaint management platform. This vulnerability allows an attacker to access other users' information by sending a POST request through the parameter id_denuncia in /backend/api/buscarDenunciaByPin.php. The flaw represents a critical Broken Access Control (CWE-862) issue that enables unauthorized access to sensitive complaint and whistleblower data.

Critical Impact

Attackers can exploit this authorization bypass to access confidential whistleblower reports and user information without authentication, potentially compromising the privacy and safety of individuals who submitted sensitive complaints.

Affected Products

• CanalDenuncia CanalDenuncia.app (all versions)

Discovery Timeline

• 2025-11-04 - CVE-2025-41113 published to NVD
• 2025-11-05 - Last updated in NVD database

Technical Details for CVE-2025-41113

Vulnerability Analysis

This vulnerability stems from a missing authorization check in the CanalDenuncia.app backend API. The affected endpoint /backend/api/buscarDenunciaByPin.php fails to properly verify whether the requesting user has permission to access the complaint record identified by the id_denuncia parameter. When a user submits a POST request with an arbitrary complaint ID, the application returns the associated complaint data without validating the requester's authorization level or ownership of the record.

This type of Insecure Direct Object Reference (IDOR) combined with missing authorization allows horizontal privilege escalation, where an attacker can enumerate complaint IDs and retrieve sensitive information belonging to other users. Given that CanalDenuncia.app is designed for handling whistleblower complaints, the exposed data could include highly sensitive disclosures, personal information, and potentially evidence of misconduct.

Root Cause

The root cause is CWE-862: Missing Authorization. The application fails to implement proper access control checks before returning complaint data. The buscarDenunciaByPin.php endpoint accepts an id_denuncia parameter and retrieves the corresponding record from the database without verifying whether the authenticated user (or any user) has the right to access that specific complaint.

Attack Vector

The attack vector is network-based and requires no authentication or user interaction. An attacker can craft HTTP POST requests to the vulnerable API endpoint with incremented or guessed id_denuncia values. Since the endpoint lacks authorization controls, each valid ID returns the associated complaint data, enabling systematic enumeration and extraction of all complaint records in the system.

The attack flow involves:

1. Identifying the vulnerable endpoint /backend/api/buscarDenunciaByPin.php
2. Sending POST requests with various id_denuncia parameter values
3. Collecting responses containing unauthorized complaint data
4. Repeating with sequential or randomized IDs to harvest additional records

Detection Methods for CVE-2025-41113

Indicators of Compromise

• Unusual volume of POST requests to /backend/api/buscarDenunciaByPin.php from a single IP address
• Sequential or patterned id_denuncia parameter values in API requests indicating enumeration attempts
• Access to complaint records by users or sessions that do not own those records
• Anomalous API response patterns showing successful data retrieval across multiple unrelated complaint IDs

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block rapid sequential requests to the vulnerable endpoint
• Monitor API access logs for unauthorized access patterns, particularly requests attempting to access multiple complaint records
• Deploy intrusion detection system (IDS) signatures for IDOR and enumeration attack patterns targeting complaint management endpoints
• Enable detailed logging on the buscarDenunciaByPin.php endpoint to capture all access attempts with associated user context

Monitoring Recommendations

• Set up real-time alerting for high-frequency API requests to complaint retrieval endpoints
• Implement user behavior analytics (UBA) to identify anomalous data access patterns
• Create dashboards to track API access by user, IP, and complaint ID to identify unauthorized access attempts
• Regularly audit access logs for signs of data harvesting or enumeration activities

How to Mitigate CVE-2025-41113

Immediate Actions Required

• Restrict access to the /backend/api/buscarDenunciaByPin.php endpoint using network-level controls or WAF rules
• Implement rate limiting on the vulnerable API endpoint to slow enumeration attempts
• Review access logs to identify any evidence of prior exploitation and assess data exposure
• Notify affected users if unauthorized access to their complaint data is detected

Patch Information

Consult the vendor advisory from INCIBE for the latest patching information. Review the INCIBE Security Notice for detailed guidance on available fixes and recommended remediation steps.

Workarounds

• Implement server-side authorization checks to verify the requesting user owns or has explicit permission to access the complaint record before returning data
• Add authentication requirements to the vulnerable endpoint if currently accessible without authentication
• Deploy input validation to restrict id_denuncia parameter values to expected formats and ranges
• Consider implementing a secure token-based access system where complaint records can only be accessed with a unique, time-limited token provided to the legitimate owner

# Example Apache configuration to restrict access to the vulnerable endpoint
<Location "/backend/api/buscarDenunciaByPin.php">
    # Restrict to internal networks only until patched
    Require ip 10.0.0.0/8 192.168.0.0/16
    
    # Enable rate limiting
    SetEnvIf Request_URI "buscarDenunciaByPin" rate_limit
    SetEnvIf rate_limit 1 rate_limit_requests=10
</Location>