CVE-2025-40662: DM Corporative CMS Path Disclosure Flaw

CVE-2025-40662 Overview

CVE-2025-40662 is an absolute path disclosure vulnerability affecting DM Corporative CMS by Acc (dmacroweb). An unauthenticated remote attacker can navigate to a non-existent file within the webroot to trigger an error response that reveals the contents of webroot/file and exposes absolute filesystem paths. The flaw is categorized under [CWE-200] (Exposure of Sensitive Information to an Unauthorized Actor) and was published to the National Vulnerability Database (NVD) on June 10, 2025. Spain's INCIBE-CERT coordinated the public advisory covering this and related DM Corporative CMS issues.

Critical Impact
Unauthenticated attackers can enumerate internal filesystem paths and webroot contents, providing reconnaissance data that supports follow-on attacks against the CMS and its hosting environment.

Affected Products

Acc DM Corporative CMS (all versions covered by the INCIBE-CERT notice)
Deployments using dmacroweb components
Web servers hosting DM Corporative CMS instances exposed to untrusted networks

Discovery Timeline

2025-06-10 - CVE-2025-40662 published to NVD
2025-10-22 - Last updated in NVD database

Technical Details for CVE-2025-40662

Vulnerability Analysis

DM Corporative CMS returns verbose error responses when a client requests a resource that does not exist within the webroot. Instead of returning a generic HTTP 404, the application emits diagnostic output that discloses absolute filesystem paths and the contents of webroot/file. This behavior allows an unauthenticated attacker to enumerate internal directory structure and harvest path information by issuing crafted HTTP requests to arbitrary non-existent resources.

The attack requires no authentication, no user interaction, and no special privileges. It can be performed remotely over the network against any exposed CMS instance. While the disclosure does not directly compromise integrity or availability, the leaked paths assist attackers in chaining the issue with file inclusion, traversal, or upload vulnerabilities documented in the related INCIBE-CERT advisory.

Root Cause

The root cause is improper error handling in the request-routing layer of DM Corporative CMS. The application surfaces low-level filesystem context, such as absolute paths and webroot file listings, in responses to requests for missing resources. Production deployments should suppress verbose diagnostics, but DM Corporative CMS lacks the configuration controls or default hardening to prevent this behavior.

Attack Vector

The attack vector is purely network-based over HTTP or HTTPS. An attacker sends a GET request to a non-existent path within the CMS webroot. The server response includes the absolute path on disk and additional file metadata. Repeated probing with different path components allows full reconnaissance of the deployed application layout. See the INCIBE CERT Notice on DM Corporate CMS Vulnerabilities for the coordinated advisory context.

Detection Methods for CVE-2025-40662

Indicators of Compromise

HTTP requests to randomized or non-existent paths under the CMS webroot, often in bursts from a single source IP
Server responses containing absolute filesystem paths such as /var/www/ or C:\inetpub\ returned in error bodies
Sequential 404 responses with unusually large payload sizes compared to standard error pages
Access log entries referencing files that do not exist in the application directory tree

Detection Strategies

Inspect web server access logs for high volumes of 404 responses originating from the same source within short time windows
Use a web application firewall (WAF) rule to flag outbound responses that contain absolute filesystem path patterns
Correlate reconnaissance against the CMS with subsequent requests targeting administrative or upload endpoints

Monitoring Recommendations

Forward CMS web server logs to a centralized logging or SIEM platform for retention and search
Alert on response bodies that include path strings outside the expected document root
Track repeated 404 patterns by client IP and User-Agent to identify automated scanners

How to Mitigate CVE-2025-40662

Immediate Actions Required

Restrict public exposure of DM Corporative CMS administration and uncommon paths using network ACLs or a reverse proxy
Configure the web server to return generic error pages and suppress application-generated diagnostics
Review web server and CMS configuration to disable directory listing and verbose error output
Monitor for the related vulnerabilities disclosed in the INCIBE-CERT advisory and apply vendor guidance as it becomes available

Patch Information

No vendor patch URL is listed in the NVD entry at the time of publication. Administrators should monitor the INCIBE CERT Notice on DM Corporate CMS Vulnerabilities and contact the vendor (dmacroweb) directly for fixed releases.

Workarounds

Place the CMS behind a reverse proxy that rewrites 404 responses to a static, generic error page
Deploy a WAF rule to strip filesystem path patterns from outbound HTTP response bodies
Disable display of detailed error messages in the underlying application runtime configuration
Limit access to the CMS to trusted IP ranges where the deployment context allows

bash

# Example nginx configuration to override application 404 responses
server {
    listen 443 ssl;
    server_name cms.example.com;

    proxy_intercept_errors on;
    error_page 404 /custom_404.html;

    location = /custom_404.html {
        root /usr/share/nginx/html;
        internal;
    }

    location / {
        proxy_pass http://dm_corporative_backend;
        proxy_hide_header X-Powered-By;
    }
}