CVE-2004-0620 in vBulletin
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in (1) newreply.php or (2) newthread.php in vBulletin 3.0.1 allows remote attackers to inject arbitrary HTML or script as other users via the Edit-panel.
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Analysis
by VulDB Data Team • 06/17/2025
The vulnerability described in CVE-2004-0620 represents a critical cross-site scripting flaw within the vBulletin 3.0.1 forum software, specifically affecting the newreply.php and newthread.php scripts. This vulnerability resides in the Edit-panel functionality where user input is not properly sanitized before being rendered back to other users. The flaw allows remote attackers to inject malicious HTML or JavaScript code that executes in the context of other users' browsers when they view the affected forum content. This represents a classic persistent XSS attack vector where malicious payloads are stored on the server and subsequently delivered to unsuspecting users during normal forum operations.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding within the vBulletin forum software's message posting and editing functionality. When users create new replies or threads, the system fails to adequately sanitize the input data before storing it in the database. The Edit-panel component specifically does not properly escape special characters or validate the content against a whitelist of safe characters, allowing attackers to inject script tags or other malicious code. This vulnerability directly maps to CWE-79 which defines Cross-Site Scripting as the failure to properly sanitize user input, and it aligns with ATT&CK technique T1566.001 for the initial compromise through malicious web content.
The operational impact of this vulnerability extends far beyond simple script injection, as it provides attackers with the ability to hijack user sessions, steal sensitive information, and potentially escalate privileges within the forum environment. An attacker could craft malicious posts that execute scripts to steal cookies, redirect users to phishing sites, or even modify forum content to spread further attacks. The persistent nature of this vulnerability means that once exploited, the malicious code remains active until manually removed from the database. This creates a sustained threat vector that can affect all forum users who view the compromised content, making it particularly dangerous in high-traffic community forums where user engagement is frequent.
The recommended mitigation strategies for this vulnerability involve immediate implementation of proper input sanitization and output encoding mechanisms within the vBulletin software. Organizations should apply the vendor-provided security patches that address this specific XSS vulnerability in the affected versions. Additionally, implementing Content Security Policy headers can provide an additional layer of protection by restricting the sources from which scripts can be loaded. Regular security audits and input validation testing should be conducted to prevent similar vulnerabilities from being introduced in future software versions. The vulnerability highlights the critical importance of secure coding practices and proper sanitization of user input in web applications, particularly those handling user-generated content in forum and discussion platforms.