CVE-2025-59545: DotNetNuke Prompt Module XSS Vulnerability

CVE-2025-59545 Overview

CVE-2025-59545 is a Cross-Site Scripting (XSS) vulnerability affecting DNN (formerly DotNetNuke), an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to version 10.1.0, the Prompt module allows execution of commands that can return raw HTML. Malicious input, even if sanitized for display elsewhere, can be executed when processed through certain commands, leading to potential script execution.

Critical Impact

This XSS vulnerability in the DNN Prompt module enables attackers to execute arbitrary JavaScript in the context of authenticated users' sessions, potentially leading to session hijacking, data theft, or privilege escalation within the CMS environment.

Affected Products

• DNN (DotNetNuke) versions prior to 10.1.0
• DNN Platform installations utilizing the Prompt module
• All DNN deployments running unpatched versions in the affected range

Discovery Timeline

• 2025-09-23 - CVE CVE-2025-59545 published to NVD
• 2025-09-29 - Last updated in NVD database

Technical Details for CVE-2025-59545

Vulnerability Analysis

This vulnerability stems from improper input validation within the DNN Prompt module (CWE-79). The Prompt module is designed to execute administrative commands and return results to users. However, the module fails to properly sanitize output when certain commands process and return raw HTML content.

Even when malicious input is sanitized for display in other parts of the application, the vulnerability exists specifically in how the Prompt module handles command output. When a user interacts with the Prompt feature, crafted payloads can bypass sanitization mechanisms and execute arbitrary JavaScript within the browser context of the victim.

The network-based attack vector with low complexity makes this vulnerability particularly concerning for publicly accessible DNN installations. An attacker with low privileges can exploit this vulnerability, though user interaction is required for successful exploitation.

Root Cause

The root cause is a failure to properly encode or sanitize HTML output returned by the Prompt module's command processing functionality. While the CMS may implement input sanitization in other areas, the specific code path through the Prompt module bypasses these protections, allowing raw HTML and JavaScript to be rendered and executed in the browser.

Attack Vector

The attack leverages the network-accessible Prompt module interface. An authenticated attacker with low privileges can craft malicious input containing JavaScript payloads. When another user (particularly an administrator) processes or views the results of commands containing this malicious content, the script executes in their browser session.

The scope of this vulnerability is changed, meaning successful exploitation can affect resources beyond the vulnerable component itself, potentially compromising other security domains such as user sessions, authentication tokens, or sensitive data accessible within the CMS.

Due to the nature of this vulnerability, no synthetic code examples are provided. Technical details regarding the specific exploitation mechanism can be found in the GitHub Security Advisory.

Detection Methods for CVE-2025-59545

Indicators of Compromise

• Unusual JavaScript payloads in Prompt module command history or logs
• Unexpected script execution errors in browser developer consoles when accessing the DNN admin interface
• Audit logs showing abnormal Prompt module usage patterns or suspicious command inputs
• Session anomalies indicating potential session hijacking following Prompt module interactions

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect XSS patterns in requests targeting the Prompt module endpoints
• Monitor application logs for encoded or obfuscated script tags and event handlers in user input fields
• Deploy Content Security Policy (CSP) headers to detect and report inline script execution attempts
• Utilize SIEM correlation rules to identify suspicious sequences of Prompt module access followed by unauthorized actions

Monitoring Recommendations

• Enable verbose logging for the DNN Prompt module to capture all command inputs and outputs
• Implement real-time alerting on any JavaScript-related patterns detected in Prompt module interactions
• Monitor for changes in user sessions or privilege levels immediately following Prompt module usage
• Regularly audit Prompt module access logs for anomalous activity patterns

How to Mitigate CVE-2025-59545

Immediate Actions Required

• Upgrade DNN (DotNetNuke) to version 10.1.0 or later immediately
• Restrict access to the Prompt module to only trusted administrators until patching is complete
• Implement additional Content Security Policy (CSP) headers to mitigate XSS impact
• Review audit logs for any indicators of prior exploitation attempts

Patch Information

DNN Software has addressed this vulnerability in version 10.1.0. Organizations running vulnerable versions should prioritize upgrading to this patched release. The security advisory is available at the GitHub Security Advisory page.

Workarounds

• Temporarily disable the Prompt module if not essential to operations until the upgrade can be performed
• Implement strict WAF rules to filter potential XSS payloads targeting the Prompt module
• Enforce principle of least privilege by limiting Prompt module access to essential personnel only
• Deploy browser-based XSS protection mechanisms and ensure modern security headers are configured

# Example: Adding Content Security Policy headers in web.config for IIS
# Add to <system.webServer><httpProtocol><customHeaders> section
# <add name="Content-Security-Policy" value="default-src 'self'; script-src 'self'; object-src 'none';" />