CVE-2025-62802: DNN (DotNetNuke) Auth Bypass Vulnerability

CVE-2025-62802 Overview

CVE-2025-62802 is an unrestricted file upload vulnerability in DNN Platform, formerly known as DotNetNuke. DNN is an open-source web content management system (CMS) built on Microsoft technologies. The default out-of-box HTML editor configuration permits unauthenticated users to upload files to the server. This exposes DNN installations to potential follow-on attacks such as malicious content hosting, phishing payload delivery, and further exploitation chains. Versions prior to 10.1.1 are affected, and the vendor has resolved the issue in version 10.1.1. The vulnerability is tracked under CWE-434: Unrestricted Upload of File with Dangerous Type.

Critical Impact
Unauthenticated attackers can upload arbitrary files through the default HTML editor configuration, creating a pivot point for follow-on attacks against DNN installations prior to 10.1.1.

Affected Products

DNN Platform (DotNetNuke) versions prior to 10.1.1
DNN installations using the default out-of-box HTML editor configuration
Self-hosted DNN CMS deployments in Microsoft/.NET environments

Discovery Timeline

2025-10-28 - CVE-2025-62802 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-62802

Vulnerability Analysis

The flaw resides in the default configuration of DNN's HTML editor component. The editor exposes file upload functionality that does not enforce authentication for callers. Unauthenticated remote users can therefore reach the upload endpoint and place files on the server. This capability is enabled by default in versions prior to 10.1.1, even though most deployments do not require anonymous uploads.

Because the issue lies in configuration and access control rather than encoding or memory handling, exploitation does not require malformed payloads. The uploaded file itself becomes the primary attack artifact. Successful uploads can serve as staging for social engineering, hosting of malicious content on the target domain, or as a building block combined with other DNN weaknesses.

Root Cause

The root cause is an insecure default configuration in the HTML editing experience shipped with DNN. Upload handlers reachable through the editor lack a required authentication check for anonymous requests. This maps to CWE-434: Unrestricted Upload of File with Dangerous Type, where the application permits file uploads without adequately restricting the identity of the uploader or the type of file being written.

Attack Vector

The attack vector is network based and requires user interaction according to the CVSS metrics published for this issue. An attacker interacts with an exposed DNN site running a vulnerable version and reaches the HTML editor upload path without authenticating. See the DNN GitHub Security Advisory GHSA-2374-6cvw-qmx6 for the vendor description of the affected surface.

No verified public proof-of-concept code is referenced in the enriched data. The vulnerability is described in prose only; see the vendor advisory for authoritative technical details.

Detection Methods for CVE-2025-62802

Indicators of Compromise

Files appearing in DNN portal upload directories that were not placed there by an authenticated administrator or content author.
HTTP requests to DNN HTML editor upload handlers originating from unauthenticated sessions or unknown IP addresses.
New or modified files under DNN Portals/ content folders with executable, script, or HTML extensions.

Detection Strategies

Review DNN application and IIS access logs for POST requests to HTML editor upload endpoints without a valid authentication cookie or session.
Correlate web server logs with file system changes in DNN content directories to identify writes tied to anonymous requests.
Inventory installed DNN versions across the environment and flag any instance reporting a version lower than 10.1.1.

Monitoring Recommendations

Enable file integrity monitoring on DNN Portals/ and upload directories, alerting on new files with executable or scriptable content types.
Instrument the web application firewall (WAF) or reverse proxy to log and alert on anonymous POST requests to editor upload URLs.
Track outbound requests from the DNN application server that could indicate an attacker validating uploaded content or chaining follow-on activity.

How to Mitigate CVE-2025-62802

Immediate Actions Required

Upgrade all DNN Platform installations to version 10.1.1 or later, which contains the vendor fix.
Audit portal upload directories for unexpected files created before the upgrade and remove any unauthorized content.
Restrict access to the DNN administration and editor endpoints to trusted networks where feasible until patching completes.

Patch Information

The vendor released the fix in DNN Platform version 10.1.1. Full details are published in the DNN GitHub Security Advisory GHSA-2374-6cvw-qmx6. Administrators should follow the DNN upgrade documentation for their deployment topology and confirm the upgrade completes across all portals and web front ends.

Workarounds

Disable or reconfigure the HTML editor so anonymous users cannot invoke file upload actions on any portal.
Enforce authentication at the reverse proxy or WAF layer for editor and upload URLs until the upgrade to 10.1.1 is applied.
Remove file write permissions from the anonymous or unauthenticated role on DNN upload directories where policy allows.

bash

# Example WAF rule concept: block anonymous requests to DNN HTML editor upload paths
# Replace <editor-upload-path> with the actual endpoint used by your DNN version
SecRule REQUEST_URI "@contains /<editor-upload-path>" \
    "id:1006202,\
     phase:1,\
     deny,\
     status:401,\
     chain,\
     msg:'Block unauthenticated DNN editor upload (CVE-2025-62802)'"
    SecRule &REQUEST_COOKIES:.authentication "@eq 0"