CVE-2025-41339: Canaldenuncia.app Auth Bypass Vulnerability

CVE-2025-41339 Overview

CVE-2025-41339 is a missing authorization vulnerability [CWE-862] in CanalDenuncia.app, a whistleblower reporting platform. The flaw resides in the /backend/api/buscarTipoDenuncia.php endpoint, which fails to validate user authorization before processing requests. An unauthenticated attacker can manipulate the id_sociedad parameter in a POST request to retrieve information belonging to other organizations using the platform. Spain's INCIBE-CERT published an advisory documenting this and related vulnerabilities affecting the application.

Critical Impact
Remote unauthenticated attackers can access confidential whistleblower data belonging to other tenants by tampering with a single POST parameter.

Affected Products

CanalDenuncia.app (all versions prior to vendor fix)
Backend API component buscarTipoDenuncia.php
Multi-tenant deployments referencing the id_sociedad identifier

Discovery Timeline

2025-11-04 - CVE-2025-41339 published to NVD
2025-11-05 - Last updated in NVD database

Technical Details for CVE-2025-41339

Vulnerability Analysis

The vulnerability is a Broken Access Control issue, specifically an Insecure Direct Object Reference (IDOR) caused by missing authorization checks. CanalDenuncia.app is a Software-as-a-Service whistleblower channel used by organizations to receive confidential reports. The id_sociedad parameter identifies the tenant organization within the multi-tenant backend.

The endpoint /backend/api/buscarTipoDenuncia.php accepts the id_sociedad value supplied by the client and returns the corresponding tenant's data. The server does not verify whether the requesting session is authorized to access the supplied identifier. As a result, any actor able to reach the API can enumerate id_sociedad values and retrieve information scoped to other organizations.

Root Cause

The root cause is the absence of a server-side authorization check binding the authenticated session, or the public client context, to the requested id_sociedad. The application trusts the client-supplied tenant identifier without cross-referencing it against an access control list. This pattern aligns with CWE-862 (Missing Authorization) and reflects a broader design flaw where tenant isolation depends solely on parameter obscurity.

Attack Vector

The attack vector is network-based and requires no authentication, no privileges, and no user interaction. An attacker crafts a POST request to /backend/api/buscarTipoDenuncia.php with a chosen id_sociedad value. By iterating numeric identifiers, the attacker enumerates organizations and harvests their associated tipoDenuncia data. No exploit code is publicly indexed at this time, and the issue is not listed in the CISA Known Exploited Vulnerabilities catalog.

Further technical details are available in the INCIBE Security Notice on Vulnerabilities.

Detection Methods for CVE-2025-41339

Indicators of Compromise

POST requests to /backend/api/buscarTipoDenuncia.php from unauthenticated sessions or unexpected source IPs
Sequential or enumerated values of the id_sociedad parameter within a short timeframe from the same client
Anomalously high request volumes targeting the buscarTipoDenuncia.php endpoint
Access patterns where a single source queries multiple distinct tenant identifiers

Detection Strategies

Implement web application firewall rules that flag requests iterating id_sociedad values across tenant boundaries
Correlate session identity with the id_sociedad parameter and alert on mismatches
Apply anomaly detection on per-IP request rates to the affected API path

Monitoring Recommendations

Forward web server and application logs for the /backend/api/ path to a centralized log platform for retention and analysis
Track HTTP 200 responses on the affected endpoint segmented by source IP and id_sociedad value
Review historical logs for prior enumeration activity that may predate vendor remediation

How to Mitigate CVE-2025-41339

Immediate Actions Required

Contact the CanalDenuncia vendor for remediation status and apply any available updates without delay
Restrict network exposure of the /backend/api/buscarTipoDenuncia.php endpoint where operationally feasible
Enable enhanced logging on the affected endpoint to support forensic review
Audit historical access logs for evidence of id_sociedad enumeration

Patch Information

No vendor patch identifier is published in the available references. Operators should consult the INCIBE Security Notice on Vulnerabilities and the CanalDenuncia vendor directly for the current fix availability and deployment guidance.

Workarounds

Enforce server-side authorization checks that validate the requesting session against the supplied id_sociedad before returning data
Deploy WAF signatures that reject requests where id_sociedad does not match the authenticated tenant context
Apply rate limiting to the affected endpoint to slow enumeration attempts
Rotate any sensitive identifiers that may have been exposed during the exposure window

bash

# Example WAF rule (ModSecurity-style) blocking unauthenticated access
# to the vulnerable endpoint pending vendor remediation
SecRule REQUEST_URI "@streq /backend/api/buscarTipoDenuncia.php" \
    "id:1004133,phase:1,deny,status:403,\
    msg:'CVE-2025-41339 - block access to vulnerable endpoint',\
    chain"
    SecRule &REQUEST_COOKIES:session "@eq 0"