CVE-2002-1803 in PHP-Nuke
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in PHP-Nuke 6.0 allows remote attackers to inject arbitrary web script or HTML via Javascript in an IMG tag.
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Analysis
by VulDB Data Team • 01/20/2025
The vulnerability identified as CVE-2002-1803 represents a critical cross-site scripting flaw within PHP-Nuke version 6.0, a widely deployed content management system and web application framework that was prevalent in the early 2000s. This vulnerability exists in the application's handling of user input within image tags, specifically when javascript code is embedded in img attributes, creating a persistent security risk that affects millions of web applications running this version of PHP-Nuke. The flaw stems from inadequate input validation and output encoding mechanisms that fail to properly sanitize user-supplied data before it is rendered in web pages, making it particularly dangerous for web applications that rely on user-generated content.
The technical implementation of this vulnerability occurs when PHP-Nuke processes image tags containing javascript code within their attributes, particularly in the src or other image properties. Attackers can exploit this weakness by crafting malicious image tags that include javascript payloads, which then get executed in the context of other users' browsers when the affected page is rendered. This represents a classic reflected cross-site scripting vulnerability where the malicious payload is stored in the application's database or configuration files and executed when legitimate users access the affected content. The vulnerability is categorized under CWE-79 as Improper Neutralization of Input During Web Page Generation, which specifically addresses the failure to properly encode or escape user input before including it in web page output. The flaw demonstrates poor security practices in input sanitization and output encoding, where the application fails to distinguish between legitimate image attributes and malicious script code.
The operational impact of CVE-2002-1803 extends far beyond simple data theft or session hijacking, as it provides attackers with complete control over user sessions and can enable more sophisticated attacks such as credential harvesting, account takeover, and data exfiltration. When exploited, this vulnerability allows attackers to execute arbitrary javascript code in the victim's browser, potentially leading to the compromise of user accounts, modification of content, or redirection to malicious sites. The attack surface is particularly broad since PHP-Nuke was commonly used for forums, news sites, and community portals where users regularly post content with image tags, making the exploitation of this vulnerability relatively straightforward. This vulnerability also maps to ATT&CK technique T1566.001 for Initial Access through Spearphishing Attachments, as attackers could leverage this weakness to deliver malicious payloads through seemingly legitimate user-generated content, and T1071.001 for Application Layer Protocol for Command and Control communications, as compromised users' browsers could be used to relay commands back to attackers.
Mitigation strategies for CVE-2002-1803 require immediate implementation of proper input validation and output encoding mechanisms throughout the PHP-Nuke application. Organizations should implement comprehensive content security policies that sanitize all user input, particularly when processing image tags or other HTML elements that may contain javascript code. The solution involves enforcing strict validation of image attributes and implementing proper HTML escaping techniques to prevent script execution in web contexts. Additionally, organizations should consider upgrading to patched versions of PHP-Nuke or migrating to more modern content management systems that have robust built-in security measures against XSS attacks. Security headers such as Content-Security-Policy should be implemented to further restrict script execution and prevent exploitation of similar vulnerabilities in the future. The remediation process should also include thorough code reviews and security testing to identify and address similar input validation weaknesses that may exist in other parts of the application, as this vulnerability highlights the importance of consistent security practices across all application components.