CVE-2005-2814 in FlatNuke
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in FlatNuke 2.5.6 allows remote attackers to inject arbitrary web script or HTML via the usr parameter in a vis_reg operation to index.php.
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Analysis
by VulDB Data Team • 07/06/2025
The vulnerability identified as CVE-2005-2814 represents a classic cross-site scripting flaw within the FlatNuke content management system version 2.5.6. This security weakness stems from inadequate input validation and sanitization mechanisms that fail to properly filter user-supplied data before it is processed and rendered within web pages. The specific attack vector involves the usr parameter within the vis_reg operation of the index.php script, where malicious actors can inject arbitrary web scripts or HTML code that executes in the context of other users' browsers.
This vulnerability falls under the Common Weakness Enumeration category CWE-79, which specifically addresses Cross-Site Scripting flaws in web applications. The flaw occurs when the application fails to properly escape or encode special characters in user input before incorporating it into dynamically generated HTML content. The affected FlatNuke version demonstrates a critical oversight in its input handling procedures, allowing attackers to bypass security controls that should prevent malicious code execution within the application's user context.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it provides attackers with the capability to execute arbitrary code in victims' browsers with the privileges of the affected user. This opens the door to session hijacking, credential theft, and the potential for further exploitation within the targeted environment. The vulnerability is particularly concerning because it operates without requiring authentication, making it accessible to anyone who can interact with the vulnerable application. Attackers can craft malicious links or embed scripts in forum posts, comments, or other user-generated content that will execute when other users view the affected pages, creating a persistent threat vector.
From an attack framework perspective, this vulnerability aligns with the MITRE ATT&CK technique T1566.001 for Phishing and T1059.001 for Command and Scripting Interpreter, as it enables attackers to deliver malicious payloads through web-based interfaces. The exploitation process typically involves crafting a malicious URL containing script code that, when executed in a victim's browser, can steal session cookies, redirect users to malicious sites, or perform actions on behalf of the authenticated user. Organizations using FlatNuke 2.5.6 should consider this vulnerability as a high-priority remediation target given its potential for widespread impact across all users of the affected system.
Mitigation strategies should focus on implementing proper input validation and output encoding mechanisms throughout the application. The recommended approach includes sanitizing all user input parameters, particularly those used in dynamic content generation, and implementing strict content security policies to prevent unauthorized script execution. Additionally, upgrading to a patched version of FlatNuke or migrating to a more secure content management system represents the most effective long-term solution. Security headers such as Content-Security-Policy should be implemented to further reduce the impact of potential XSS attacks, while regular security audits and input validation testing should be conducted to prevent similar vulnerabilities from emerging in the future.