CVE-2023-41538 in PHP Forum Script
Summary
by MITRE • 08/30/2023
phpjabbers PHP Forum Script 3.0 is vulnerable to Cross Site Scripting (XSS) via the keyword parameter.
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Analysis
by VulDB Data Team • 02/01/2026
The vulnerability CVE-2023-41538 affects phpjabbers PHP Forum Script version 3.0 and represents a classic cross site scripting flaw that can be exploited through the keyword parameter. This type of vulnerability falls under the CWE-79 category known as "Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')", which is one of the most prevalent and dangerous web application security issues. The vulnerability specifically manifests when user-supplied input from the keyword parameter is not properly sanitized or encoded before being rendered back to users in the web application's response.
The technical exploitation of this XSS vulnerability occurs when an attacker submits malicious script code through the keyword parameter during forum searches or other functionality that processes user input. The application fails to implement proper input validation and output encoding mechanisms, allowing the malicious payload to be executed in the context of other users' browsers. This creates a persistent threat where any user who views pages containing the reflected or stored malicious content becomes a potential victim of the attack. The vulnerability can be leveraged for various malicious purposes including session hijacking, credential theft, defacement of the forum content, or redirection to malicious websites.
The operational impact of this vulnerability extends beyond simple data theft or defacement. Attackers can use this XSS flaw to establish persistent access to the forum environment, potentially compromising the entire user base that interacts with the vulnerable application. The attack surface is particularly concerning given that forums typically contain sensitive user information including personal details, messages, and potentially confidential communications between users. This vulnerability can be exploited by attackers without requiring authentication, making it a critical concern for any organization relying on this forum script. The ATT&CK framework categorizes this as a web application attack technique under the T1059.007 sub-technique for "Scripting" which involves using scripting languages to perform malicious activities.
Mitigation strategies for CVE-2023-41538 should focus on implementing robust input validation and output encoding practices throughout the application. The most effective approach involves sanitizing all user-supplied input through proper escaping mechanisms before rendering any content back to users. This includes implementing context-specific encoding such as HTML entity encoding for output contexts, and using secure coding practices that prevent the injection of malicious scripts. Organizations should also consider implementing Content Security Policy (CSP) headers as an additional defense-in-depth measure to limit the execution of unauthorized scripts. Regular security audits and code reviews should be conducted to identify similar vulnerabilities in other input parameters and application components. The vulnerability highlights the critical importance of following secure coding guidelines and implementing proper input sanitization as outlined in OWASP Top Ten and other industry security standards. Updates to the phpjabbers PHP Forum Script to version 3.1 or later should be prioritized as these releases typically contain patches addressing such XSS vulnerabilities.