CVE-2004-0339 in phpBB
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in ViewTopic.php in phpBB, possibly 2.0.6c and earlier, allows remote attackers to execute arbitrary script or HTML as other users via the postorder parameter.
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Analysis
by VulDB Data Team • 06/22/2018
The vulnerability identified as CVE-2004-0339 represents a critical cross-site scripting flaw within the phpBB bulletin board system, specifically affecting versions 2.0.6c and earlier. This security weakness resides in the ViewTopic.php script which processes user inputs without proper sanitization, creating an avenue for malicious actors to inject arbitrary HTML and script code into the application's response. The vulnerability manifests when the postorder parameter is manipulated by an attacker, allowing them to execute code within the context of other users' browsers who view the affected topic. This type of vulnerability falls under the Common Weakness Enumeration category CWE-79, which specifically addresses improper neutralization of input during web page generation, making it a classic example of client-side code injection.
The technical exploitation of this vulnerability occurs when phpBB fails to properly validate or escape user-supplied input from the postorder parameter before rendering it in the web page output. When a victim visits a topic page where the malicious payload has been injected through the vulnerable parameter, their browser executes the embedded script code as if it originated from the legitimate phpBB application. This allows attackers to perform various malicious activities including session hijacking, credential theft, defacement of forum content, or redirection to malicious websites. The vulnerability's impact extends beyond simple script execution as it can be leveraged to establish persistent malicious presence within the forum environment, potentially compromising all users who interact with the affected content. The attack vector requires minimal privileges since it operates entirely through web-based input manipulation without requiring authentication or direct system access.
The operational consequences of this vulnerability are significant for phpBB installations, as it enables attackers to compromise the integrity and confidentiality of user sessions and data. Any user who views a topic containing malicious content can become a victim of the XSS attack, potentially leading to widespread compromise of forum user accounts. The vulnerability also undermines the trust relationship between forum administrators and users, as malicious actors can manipulate forum content to appear legitimate. Security professionals should note that this vulnerability aligns with ATT&CK technique T1566.001, which describes the use of malicious content to gain access to systems through phishing or social engineering methods. Organizations using vulnerable versions of phpBB face potential data breaches, reputational damage, and regulatory compliance violations if user credentials or sensitive information is compromised through this vector.
Mitigation strategies for CVE-2004-0339 should prioritize immediate application of security patches released by the phpBB development team for versions 2.0.6d and later. System administrators must implement proper input validation and output encoding mechanisms to prevent user-supplied data from being executed as code within the browser context. The implementation of Content Security Policy headers can provide additional protection against XSS attacks by restricting script execution sources. Organizations should also consider deploying web application firewalls to detect and block malicious input patterns targeting this vulnerability. Regular security audits and vulnerability assessments should be conducted to identify similar input validation weaknesses in other applications. The remediation process must include comprehensive testing to ensure that the applied fixes do not introduce regressions in legitimate forum functionality while maintaining the security posture against future exploitation attempts.