CVE-2010-4207 in YUI
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the Flash component infrastructure in YUI 2.4.0 through 2.8.1, as used in Bugzilla, Moodle, and other products, allows remote attackers to inject arbitrary web script or HTML via vectors related to charts/assets/charts.swf.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 09/28/2021
The vulnerability described in CVE-2010-4207 represents a critical cross-site scripting flaw within the Yahoo User Interface (YUI) library version 2.4.0 through 2.8.1. This issue specifically affects the Flash component infrastructure, particularly the charts.swf file located in the charts/assets directory. The vulnerability arises from insufficient input validation and output encoding mechanisms within the YUI Flash components, creating a pathway for malicious actors to execute arbitrary web scripts or HTML code within the context of affected applications. This flaw impacts numerous web applications that integrate YUI libraries, including prominent platforms such as Bugzilla and Moodle, making it a widespread concern across the software ecosystem.
The technical exploitation of this vulnerability occurs through the manipulation of parameters passed to the Flash component within the charts.swf file. When applications using YUI libraries process user input and pass it directly to the Flash component without proper sanitization or encoding, attackers can inject malicious scripts that execute within the victim's browser context. The vulnerability falls under CWE-79, which specifically addresses cross-site scripting flaws in software applications. This weakness allows attackers to bypass the same-origin policy that normally protects web browsers from malicious script execution, enabling them to access session cookies, perform actions on behalf of users, or redirect them to malicious sites. The attack vector involves the Flash component's handling of data passed from web applications, where the component fails to properly escape or validate user-supplied parameters before rendering them within the Flash environment.
The operational impact of this vulnerability extends beyond individual application compromises to potentially affect entire user bases across multiple platforms. Since Bugzilla, Moodle, and other applications rely on the vulnerable YUI versions, attackers can exploit this weakness to target users of these systems simultaneously. The consequences include unauthorized access to sensitive information, session hijacking, data exfiltration, and potential privilege escalation within affected applications. Organizations using these vulnerable systems face significant risks including compromised user data, regulatory compliance violations, and reputational damage. The vulnerability is particularly concerning because it affects widely deployed software components, meaning that a single exploited instance can compromise numerous applications that depend on YUI for charting functionality. This creates a cascading effect where a single vulnerability in a foundational library can impact hundreds or thousands of applications across different organizations.
Organizations should immediately implement comprehensive mitigation strategies to address this vulnerability. The primary recommendation involves upgrading to patched versions of YUI libraries, specifically versions 2.8.2 or later where the XSS vulnerability has been addressed. Additionally, implementing proper input validation and output encoding mechanisms at the application level can provide defense-in-depth measures. Web application firewalls should be configured to detect and block suspicious Flash component parameter patterns, while content security policies can be enforced to limit script execution capabilities. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of the vulnerable YUI components within the application stack. The ATT&CK framework categorizes this vulnerability under T1059.007 for scripting languages and T1566 for spearphishing with social engineering, highlighting the need for both technical and user awareness measures to prevent exploitation. Organizations should also consider implementing automated patch management processes to ensure timely deployment of security updates and maintain inventory tracking of all third-party components to quickly identify and remediate similar vulnerabilities in the future.