CVE-2007-2909 in vBulletin
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in calendar.php in Jelsoft vBulletin 3.6.x before 3.6.7 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors, related to the vb_calendar366_xss_fix_plugin.xml update.
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Analysis
by VulDB Data Team • 09/03/2018
The vulnerability identified as CVE-2007-2909 represents a cross-site scripting flaw located within the calendar.php component of Jelsoft vBulletin 3.6.x versions prior to 3.6.7. This issue stems from inadequate input validation and output encoding mechanisms that fail to properly sanitize user-supplied data before rendering it within web pages. The vulnerability specifically manifests through the vb_calendar366_xss_fix_plugin.xml update process, indicating that the security patch mechanism itself may have contained implementation flaws or was insufficiently robust. Such vulnerabilities fall under the CWE-79 category of Cross-Site Scripting, which is classified as a critical web application security weakness that allows attackers to execute malicious scripts in the context of other users' browsers.
The technical exploitation of this vulnerability occurs when remote attackers submit malicious payloads through unspecified input vectors within the calendar functionality of the vBulletin platform. These input vectors could include calendar event titles, descriptions, or other user-editable fields that are processed by the calendar.php script. The vulnerability's nature suggests that the application fails to properly escape or encode special characters in user-provided content, allowing attackers to inject HTML tags or JavaScript code that executes when other users view the affected calendar entries. This type of flaw enables attackers to perform various malicious activities including session hijacking, credential theft, defacement of content, or redirection to malicious websites.
The operational impact of CVE-2007-2909 extends beyond simple data corruption or unauthorized access, as it provides attackers with a persistent vector for executing malicious code within the context of legitimate user sessions. When exploited successfully, this vulnerability allows attackers to manipulate the calendar functionality and potentially gain unauthorized access to user data or perform actions on behalf of authenticated users. The attack surface is particularly concerning given that calendar components often contain sensitive personal information and are frequently accessed by multiple users within organizational environments. This vulnerability aligns with ATT&CK technique T1531 for 'Modify Existing Service' and T1059.007 for 'Command and Scripting Interpreter: JavaScript', as it enables attackers to execute JavaScript code within user browsers.
Organizations utilizing affected vBulletin versions should prioritize immediate remediation through the official 3.6.7 patch release or equivalent security updates that address the XSS vulnerability in the calendar component. The mitigation strategy should include comprehensive input validation and output encoding mechanisms throughout the application, particularly for all user-supplied content that is rendered in web pages. Security measures should implement proper HTML escaping and context-specific encoding for all dynamic content, as recommended by the OWASP Cross-Site Scripting Prevention Cheat Sheet. Additionally, organizations should conduct thorough security assessments of their web applications to identify similar vulnerabilities in other components, as this vulnerability demonstrates the importance of consistent security practices across all application modules. The vulnerability also highlights the critical need for proper plugin and update management processes, as the issue specifically relates to the calendar plugin update mechanism, suggesting that inadequate validation of third-party components can introduce security weaknesses into the overall application architecture.