CVE-2001-1524 in PHP-Nuke
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in PHP-Nuke 5.3.1 and earlier allows remote attackers to inject arbitrary web script or HTML via the (1) uname parameter in user.php, (2) ttitle, letter and file parameters in modules.php, (3) subject, story and storyext parameters in submit.php, (4) upload parameter in admin.php and (5) fname parameter in friend.php.
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Analysis
by VulDB Data Team • 09/24/2025
This cross-site scripting vulnerability in PHP-Nuke 5.3.1 and earlier versions represents a critical security flaw that enables remote attackers to execute malicious scripts within the context of users' browsers. The vulnerability stems from insufficient input validation and output encoding mechanisms across multiple entry points within the PHP-Nuke framework, making it one of the most widespread XSS flaws affecting web applications built on this platform. The flaw specifically manifests when user-supplied data is directly incorporated into web page responses without proper sanitization, creating opportunities for attackers to inject malicious HTML or JavaScript code that executes in the victim's browser context.
The technical implementation of this vulnerability spans five distinct parameter injection points across different PHP files within the application. The uname parameter in user.php allows attackers to inject malicious content through user identification fields, while the ttitle, letter, and file parameters in modules.php provide additional attack vectors through module title and file handling mechanisms. The submit.php file contains vulnerabilities through subject, story, and storyext parameters that process user-submitted content, and the admin.php file exposes the upload parameter as another injection point. Finally, the fname parameter in friend.php creates a pathway for malicious input through friend relationship management functionality. These diverse injection points demonstrate the comprehensive nature of the vulnerability and its deep integration within the application's core functionality.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform session hijacking, deface websites, steal user credentials, and conduct phishing attacks against authenticated users. The attack surface is particularly concerning given that PHP-Nuke was widely deployed in content management systems, forums, and web applications during this period, meaning that successful exploitation could compromise numerous websites simultaneously. According to the CWE database, this vulnerability maps to CWE-79 which specifically addresses cross-site scripting flaws, and aligns with ATT&CK technique T1566.001 for initial access through malicious web content. The vulnerability's exploitation requires no special privileges beyond standard user access and can be executed through simple web browser interactions, making it highly dangerous in production environments.
Mitigation strategies for this vulnerability involve implementing comprehensive input validation and output encoding mechanisms across all user-supplied parameters. Organizations should immediately upgrade to patched versions of PHP-Nuke, as the vulnerability was addressed in subsequent releases. Input sanitization should include proper HTML escaping, character encoding, and validation of all parameter values before processing. The implementation of Content Security Policy headers can provide additional protection against script execution, while proper output encoding ensures that malicious scripts cannot execute even if input validation fails. Security monitoring should include detection of suspicious parameter patterns and regular vulnerability assessments to identify similar issues in other application components. This vulnerability serves as a classic example of why input validation and output encoding must be implemented consistently across all application layers, as demonstrated by the ATT&CK framework's emphasis on preventing malicious code execution through proper application security controls.