CVE-2002-2235 in vBulletin
Summary
by MITRE
member2.php in vBulletin 2.2.9 and earlier does not properly restrict the $perpage variable to be an integer, which causes an error message to be reflected back to the user without quoting, which facilitates cross-site scripting (XSS) and possibly other attacks.
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Analysis
by VulDB Data Team • 02/01/2025
The vulnerability identified as CVE-2002-2235 affects vBulletin versions 2.2.9 and earlier, specifically within the member2.php script where improper input validation allows malicious users to inject arbitrary data into the $perpage variable. This flaw stems from insufficient sanitization of user-supplied parameters before they are processed and displayed within the application's output, creating a pathway for attackers to manipulate the application's behavior through crafted HTTP requests. The vulnerability exists in the context of web application security where proper input validation and output encoding are fundamental defensive measures against various injection attacks.
The technical implementation of this vulnerability occurs when the application fails to validate that the $perpage parameter contains only numeric characters, allowing attackers to submit non-integer values that are then reflected back to users without proper HTML escaping or quoting mechanisms. This lack of input sanitization creates a classic cross-site scripting vulnerability where malicious payloads can be executed within the context of other users' browsers when they view the affected page. The reflected nature of this XSS vulnerability means that the malicious code is not stored on the server but rather injected through the vulnerable parameter and immediately executed upon page rendering.
The operational impact of this vulnerability extends beyond simple XSS exploitation as it provides attackers with potential access to user sessions, credential theft, and redirection to malicious websites. The vulnerability can be leveraged to create persistent XSS attacks that target unsuspecting users who visit the affected pages, potentially leading to account takeovers or data exfiltration. According to CWE-79, this vulnerability maps directly to Cross-Site Scripting flaws where improper neutralization of input data leads to execution of unintended code in the victim's browser. The attack surface is particularly concerning given that vBulletin was widely used for forums and community platforms where user interaction is high and session management is critical.
Mitigation strategies for this vulnerability require immediate implementation of proper input validation and output encoding practices. The primary fix involves ensuring that all user-supplied parameters, particularly those used in dynamic content generation, are validated to contain only expected data types before processing. This includes implementing strict integer validation for the $perpage parameter and applying proper HTML escaping or quoting mechanisms when displaying user input back to the browser. Organizations should also consider implementing Content Security Policy headers to limit the execution of unauthorized scripts and establish proper input sanitization routines that align with OWASP Top Ten security recommendations. The vulnerability demonstrates the critical importance of input validation and output encoding in preventing injection attacks, with the specific remediation approach aligning with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1566 for Phishing, as attackers can leverage such flaws to execute malicious scripts and establish persistent access to user sessions.