A critical stored cross-site scripting vulnerability has emerged in the popular DotNetNuke (DNN) Platform, threatening websites powered by this widely-used content management system.

The vulnerability, tracked as CVE-2025-59545 with a severity score of 9.1 out of 10, affects all DNN Platform versions prior to 10.1.0 and allows attackers to execute malicious scripts through the platform’s Prompt module.

The security flaw stems from the way DNN’s Prompt module processes commands that return raw HTML output.

While the platform typically sanitizes user-submitted data before displaying it in entry forms, the Prompt module bypasses these standard sanitation mechanisms by treating command output as executable HTML.

This creates a dangerous pathway for attackers to inject and execute malicious scripts within the application’s trusted environment.

The vulnerability poses significant risks to organizations running affected DNN installations, particularly when exploited in super-user contexts.

Attackers can craft malicious input containing embedded scripts or harmful markup that, when processed through specific Prompt commands, gets rendered directly in browsers without proper security validation.

Github analysts identified this critical weakness through comprehensive security research, highlighting the importance of continuous platform monitoring for emerging threats.

Attackers leverage this vulnerability by targeting the network-accessible Prompt module with relatively low complexity attack vectors.

The exploitation requires minimal privileges and user interaction, making it an attractive target for malicious actors seeking to compromise DNN-powered websites.

Once successfully exploited, the vulnerability can impact system confidentiality, integrity, and availability across changed security scopes.

Exploitation Mechanism and Attack Vectors

The attack mechanism revolves around the fundamental design flaw in how the Prompt module handles command execution and output rendering.

When an attacker submits crafted input through the module, the system fails to distinguish between legitimate HTML output and malicious script content.

The vulnerability manifests when specific commands process untrusted data and return it as HTML, effectively bypassing the application’s security boundaries.

The attack vector follows a stored XSS pattern, categorized under CWE-79 weakness classification.

Malicious payloads can be persistently stored within the system and executed whenever the compromised content is accessed.

This persistence factor amplifies the vulnerability’s impact, as it affects not only the initial victim but potentially all subsequent users who interact with the compromised content.

Organizations using affected DNN Platform versions should immediately upgrade to version 10.1.0, which includes comprehensive patches addressing this critical security flaw.

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