CVE-2025-64095 Overview
CVE-2025-64095 is a critical vulnerability affecting DNN (formerly DotNetNuke), an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to version 10.1.1, the default HTML editor provider allows unauthenticated file uploads, and uploaded images can overwrite existing files on the server. This vulnerability enables an unauthenticated attacker to upload and replace existing files, allowing website defacement and, when combined with other issues, injection of XSS payloads.
Critical Impact
Unauthenticated attackers can upload malicious files and overwrite existing website content, leading to website defacement and potential XSS attacks without requiring any authentication.
Affected Products
- DNN (DotNetNuke) versions prior to 10.1.1
- dnnsoftware dotnetnuke
Discovery Timeline
- 2025-10-28 - CVE-2025-64095 published to NVD
- 2025-11-03 - Last updated in NVD database
Technical Details for CVE-2025-64095
Vulnerability Analysis
This vulnerability is classified as CWE-434 (Unrestricted Upload of File with Dangerous Type). The core issue resides in the default HTML editor provider within DNN, which fails to properly authenticate users before allowing file upload operations. Additionally, the file handling mechanism does not implement adequate protections against file overwrites, enabling attackers to replace legitimate files with malicious content.
The vulnerability is particularly concerning because it requires no authentication (PR:N in CVSS vector), no user interaction (UI:N), and can be exploited remotely over the network (AV:N) with low attack complexity (AC:L). When successfully exploited, an attacker can achieve high impact on confidentiality, integrity, and availability of the affected system.
Root Cause
The root cause of CVE-2025-64095 lies in the insufficient access control implementation within the HTML editor's file upload functionality. The default configuration does not enforce authentication checks before processing file upload requests. Furthermore, the system lacks proper validation to prevent uploaded files from overwriting existing files on the server, creating a path for both content manipulation and potential code execution scenarios.
Attack Vector
An attacker can exploit this vulnerability by sending crafted HTTP requests to the DNN platform's file upload endpoint without any authentication credentials. The attack flow involves:
- Identifying a vulnerable DNN installation running a version prior to 10.1.1
- Crafting a file upload request targeting the HTML editor provider's upload functionality
- Uploading malicious content designed to overwrite existing legitimate files
- Optionally chaining with XSS payloads to execute client-side attacks against website visitors
The vulnerability mechanism involves the HTML editor's file handling component failing to validate both authentication status and file destination paths. When an unauthenticated request is received, the server processes the upload without verifying the user's identity or checking if the target filename already exists. This allows attackers to replace critical website assets such as images, JavaScript files, or other resources with malicious alternatives. For detailed technical information, refer to the DNN Platform Security Advisory.
Detection Methods for CVE-2025-64095
Indicators of Compromise
- Unexpected file modifications or new files appearing in web-accessible directories
- HTTP requests to file upload endpoints from unauthenticated sources
- Modified timestamps on static assets (images, scripts) without corresponding administrative actions
- Web server logs showing unusual POST requests to HTML editor endpoints
Detection Strategies
- Monitor web server access logs for unauthenticated POST requests targeting file upload endpoints
- Implement file integrity monitoring (FIM) on critical web content directories
- Deploy web application firewall (WAF) rules to detect and block suspicious file upload attempts
- Review HTTP traffic for upload requests lacking proper authentication headers
Monitoring Recommendations
- Enable detailed logging for the DNN HTML editor component
- Configure alerts for file changes in the CMS content directories
- Monitor for anomalous traffic patterns indicating scanning or exploitation attempts
- Implement network-level monitoring for connections to known malicious IPs following any suspicious uploads
How to Mitigate CVE-2025-64095
Immediate Actions Required
- Upgrade DNN (DotNetNuke) to version 10.1.1 or later immediately
- Review recent file uploads and modifications for signs of compromise
- Audit web server logs for evidence of exploitation attempts
- Consider temporarily disabling the HTML editor's file upload functionality until patching is complete
Patch Information
DNN Software has addressed this vulnerability in version 10.1.1. Organizations running affected versions should prioritize upgrading to the patched release. For complete patch details and release notes, consult the GitHub Security Advisory.
Workarounds
- Restrict access to file upload endpoints at the web server or firewall level
- Implement additional authentication requirements for HTML editor functionality
- Configure the web server to block unauthenticated requests to known upload paths
- Deploy a web application firewall with rules to filter malicious upload attempts
# Example IIS URL Rewrite rule to block unauthenticated uploads (temporary mitigation)
# Add to web.config in the DNN root directory
# Note: This is a temporary workaround - apply the official patch as soon as possible
# Consult the security advisory for specific endpoint paths to restrict
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
