CVE-2008-4871 in My Little Forum
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in My Little Forum 1.75 and 2.0 Beta 23 allows remote attackers to inject arbitrary web script or HTML via BBcode IMG tags.
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Analysis
by VulDB Data Team • 12/05/2017
The vulnerability identified as CVE-2008-4871 represents a critical cross-site scripting flaw within My Little Forum versions 1.75 and 2.0 Beta 23, classified under CWE-79 as Improper Neutralization of Input During Web Page Generation. This vulnerability specifically targets the forum's handling of BBcode IMG tags, which are commonly used for embedding images within forum posts. The flaw arises from insufficient input validation and sanitization mechanisms that fail to properly escape or filter user-supplied data before rendering it in web pages. Attackers can exploit this weakness by crafting malicious BBcode tags containing embedded JavaScript code or HTML payloads within the image source attributes. When other users view affected forum posts, the malicious code executes in their browsers within the context of the vulnerable forum's domain, potentially leading to session hijacking, credential theft, or redirection to malicious sites.
The technical exploitation of this vulnerability demonstrates a classic XSS attack vector where the attacker leverages the forum's BBcode parsing functionality to inject malicious content. The vulnerability exists because the application does not adequately sanitize the src attribute of IMG tags, allowing attackers to include javascript: URIs or other malicious protocols. This flaw operates at the application layer and can be categorized under the ATT&CK technique T1059.007 for Command and Scripting Interpreter: JavaScript. The impact extends beyond simple script execution as it enables persistent XSS attacks that can remain active for extended periods, particularly when the vulnerable forum maintains user sessions and displays posts across multiple pages.
The operational consequences of this vulnerability are severe for forum administrators and end users alike. Compromised user sessions could lead to unauthorized access to personal accounts, posting of malicious content, or data exfiltration from the forum environment. The vulnerability affects the integrity and confidentiality of the forum's user base, potentially enabling attackers to establish persistent footholds within the community. Organizations using My Little Forum versions 1.75 and 2.0 Beta 23 face significant risk of reputational damage and potential regulatory compliance violations if user data is compromised. The vulnerability's persistence in beta releases indicates inadequate security testing during development, highlighting the importance of comprehensive input validation and output encoding practices.
Mitigation strategies for CVE-2008-4871 require immediate patching of affected My Little Forum installations to the latest stable versions that address the XSS vulnerability. Organizations should implement proper input validation and output encoding for all BBcode processing, specifically ensuring that IMG tag attributes undergo strict sanitization before rendering. The implementation of Content Security Policy headers can provide additional defense-in-depth measures to prevent execution of unauthorized scripts. Regular security audits and code reviews should focus on input handling mechanisms, particularly for markup languages and formatting tags. According to ATT&CK framework guidance, administrators should also consider implementing web application firewalls to detect and block suspicious BBcode patterns. The vulnerability serves as a reminder of the critical importance of proper input sanitization and the need for comprehensive security testing throughout the software development lifecycle, as outlined in OWASP Top Ten security principles.