CVE-2002-2340 in Phorum
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in read.php in Phorum 3.3.2a allows remote attackers to inject arbitrary web script or HTML via (1) the t parameter or (2) the body of an email response.
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Analysis
by VulDB Data Team • 08/28/2025
The vulnerability described in CVE-2002-2340 represents a critical cross-site scripting flaw within the Phorum 3.3.2a web forum software, specifically affecting the read.php script. This vulnerability falls under the Common Weakness Enumeration category CWE-79, which defines improper neutralization of input during web output rendering as a fundamental weakness in web application security. The flaw enables malicious actors to execute arbitrary web scripts or HTML code within the context of other users' browsers, potentially compromising the confidentiality and integrity of user sessions and data.
The technical exploitation occurs through two distinct attack vectors that target the t parameter and the email response body within the Phorum forum system. When a user navigates to a maliciously crafted URL containing the t parameter or when an email response contains malicious script code within its body, the vulnerable read.php script fails to properly sanitize or escape user-supplied input before rendering it in the web page output. This lack of input validation and output encoding creates an environment where attacker-controlled code can be executed in the victim's browser context, potentially leading to session hijacking, credential theft, or malicious redirection.
The operational impact of this vulnerability extends beyond simple script execution, as it fundamentally undermines the trust model of web applications and user sessions. When exploited successfully, this XSS vulnerability allows attackers to steal session cookies, modify user interface elements, redirect users to malicious sites, or even perform actions on behalf of authenticated users. The attack requires minimal privileges and can be executed through simple email-based social engineering or direct URL manipulation, making it particularly dangerous in forum environments where users regularly interact with content from unknown sources. The vulnerability affects all users who access the affected Phorum installation, including administrators, making it a critical concern for any organization relying on this forum software.
Mitigation strategies for this vulnerability must address both the immediate security gap and establish comprehensive input validation mechanisms. Organizations should implement proper output encoding for all user-supplied content, particularly when rendering data in web contexts. The recommended approach involves applying context-specific encoding techniques such as HTML entity encoding for content rendered in HTML contexts, JavaScript encoding for script contexts, and URL encoding for URL contexts. Additionally, implementing a robust Content Security Policy (CSP) can provide defense-in-depth protection against XSS attacks by restricting the sources from which scripts can be loaded and executed. Regular security updates and patches should be applied immediately upon availability, as this vulnerability was present in version 3.3.2a and likely affected other versions of the Phorum software. The mitigation process should also include comprehensive security testing, including automated scanning and manual penetration testing, to identify similar vulnerabilities in other components of the web application stack. Organizations should also consider implementing web application firewalls and monitoring systems to detect and prevent exploitation attempts targeting known XSS vulnerabilities.