CVE-2014-4958 in ASP.NET AJAX RadEditor control
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Telerik UI for ASP.NET AJAX RadEditor control 2014.1.403.35, 2009.3.1208.20, and other versions allows remote attackers to inject arbitrary web script or HTML via CSS expressions in style attributes.
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Analysis
by VulDB Data Team • 03/29/2022
The vulnerability CVE-2014-4958 represents a critical cross-site scripting flaw within the Telerik UI for ASP.NET AJAX RadEditor control, specifically affecting versions 2014.1.403.35, 2009.3.1208.20, and other affected releases. This vulnerability resides in the rich text editing component's handling of CSS style attributes, creating a pathway for remote attackers to execute malicious code within victim browsers. The flaw manifests when the editor processes user-supplied content containing CSS expressions within style attributes, allowing attackers to inject arbitrary web scripts or HTML code that gets executed in the context of legitimate users.
The technical implementation of this vulnerability stems from inadequate input sanitization and validation within the RadEditor control's CSS processing logic. When the editor encounters CSS expressions within style attributes, it fails to properly escape or filter these expressions before rendering them in the browser context. This processing error creates a direct vector for XSS attacks, as the CSS expressions can contain JavaScript code that executes when the page renders. The vulnerability specifically targets the control's ability to handle dynamic style attributes, making it particularly dangerous in web applications that rely on user-generated content processing. According to CWE classification, this maps to CWE-79: Improper Neutralization of Input During Web Page Generation, which represents one of the most common and dangerous web application vulnerabilities.
The operational impact of CVE-2014-4958 extends beyond simple script execution, potentially enabling attackers to perform session hijacking, deface websites, steal sensitive information, or redirect users to malicious domains. Attackers can craft malicious CSS expressions that exploit the vulnerability through various attack vectors including email attachments, web forms, or comment sections where the RadEditor control is implemented. The remote nature of this vulnerability means that attackers do not require physical access to the target system, making it particularly dangerous for web applications with public-facing interfaces. This vulnerability directly aligns with ATT&CK technique T1566.001: Phishing for Information, as it provides attackers with a mechanism to deliver malicious payloads that can capture user credentials or sensitive data.
Organizations utilizing the affected Telerik RadEditor controls face significant security risks, particularly in applications handling user-generated content where the vulnerability can be exploited through multiple entry points. The remediation process involves applying the vendor-provided patches and updates, which typically include enhanced input validation and CSS expression filtering mechanisms. Security teams should implement comprehensive monitoring for suspicious CSS content and consider deploying web application firewalls to detect and block malicious payloads. Additionally, organizations should conduct thorough code reviews to identify all instances where the RadEditor control is used, ensuring that proper input sanitization is implemented at multiple layers of the application architecture. The vulnerability demonstrates the importance of validating and sanitizing all user-supplied content, particularly within rich text editing components that process complex styling attributes.