CVE-2008-3874 in Vanilla
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in account.php in Lussumo Vanilla 1.1.5-rc1, 1.1.4, and earlier allows remote authenticated users to inject arbitrary web script or HTML via the Value field (aka Label ==> Value pairs). NOTE: some of these details are obtained from third party information.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 10/08/2018
The vulnerability identified as CVE-2008-3874 represents a critical cross-site scripting flaw within the Lussumo Vanilla forum software version 1.1.5-rc1 and earlier releases. This vulnerability specifically targets the account.php script and affects authenticated users who possess the ability to manipulate form fields within the application's administrative interface. The flaw manifests when users can inject malicious scripts through the Value field of Label ==> Value pairs, creating a persistent XSS vector that can be exploited by attackers who have already gained access to legitimate user accounts. The vulnerability's classification as a remote authenticated XSS attack means that an attacker must first obtain valid credentials to exploit this weakness, but once achieved, the impact can be severe as it allows for the execution of arbitrary code within the context of the victim's browser session.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding within the Vanilla forum's account management functionality. When administrators or users modify configuration settings through the Label ==> Value pair interface, the application fails to properly sanitize or encode user-supplied data before rendering it back to the browser. This lack of proper sanitization creates an environment where malicious scripts can be injected and subsequently executed whenever the affected page is loaded. The vulnerability aligns with CWE-79, which specifically addresses Cross-Site Scripting flaws, and demonstrates a classic case of insufficient input sanitization where user-controllable data flows directly into the application's output without proper security controls. The attack vector operates through the manipulation of form fields that are designed to store configuration values, making this a particularly insidious vulnerability as it leverages legitimate administrative functions to deliver malicious payloads.
The operational impact of CVE-2008-3874 extends beyond simple script injection, as authenticated users with malicious intent can leverage this vulnerability to perform session hijacking, steal sensitive information, or redirect users to malicious websites. An attacker who successfully exploits this vulnerability can execute scripts that capture cookies, modify page content, or even redirect users to phishing sites designed to harvest additional credentials. The persistent nature of the vulnerability means that once injected, malicious scripts will execute every time the affected page is accessed by any user, potentially affecting multiple victims within the forum community. This vulnerability represents a significant threat to user privacy and application integrity, as it allows attackers to maintain persistent access to forum data and user sessions, potentially compromising the entire platform's security posture.
Mitigation strategies for this vulnerability require immediate implementation of proper input validation and output encoding mechanisms within the Vanilla forum software. Organizations should implement strict sanitization of all user-supplied data before rendering it in web pages, particularly within administrative interfaces where configuration values are stored and retrieved. The solution involves implementing comprehensive HTML entity encoding for all output, particularly when dealing with user-controllable data that flows through the Label ==> Value pair system. Security patches should be applied immediately to upgrade to versions of Vanilla that have addressed this vulnerability, as the software developers would have implemented proper input validation controls. Additionally, organizations should consider implementing Content Security Policy (CSP) headers to provide an additional layer of protection against XSS attacks, and establish regular security auditing procedures to identify potential input validation gaps within their web applications. This vulnerability serves as a reminder of the critical importance of proper input sanitization and output encoding in web application security, particularly within administrative interfaces where users have elevated privileges and can cause significant damage when exploited.