CVE-2014-6420 in LiveComments
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Livefyre LiveComments 3.0 allows remote attackers to inject arbitrary web script or HTML via the name of an uploaded picture.
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Analysis
by VulDB Data Team • 02/14/2025
The CVE-2014-6420 vulnerability represents a critical cross-site scripting flaw in Livefyre LiveComments version 3.0 that exposes web applications to remote code execution through user-uploaded media. This vulnerability specifically targets the handling of image file names during the upload process, creating an avenue for attackers to inject malicious scripts that can execute in the context of other users' browsers. The flaw occurs when the system fails to properly sanitize or escape special characters in file names, allowing attackers to embed script tags or other malicious code within the image metadata or file naming convention. This type of vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is classified as a fundamental weakness in web application security that enables attackers to inject client-side scripts into web pages viewed by other users.
The technical implementation of this vulnerability exploits the trust model inherent in web applications where user-provided data is often treated as safe without proper validation or sanitization. When users upload images to the Livefyre LiveComments system, the application processes the file name without adequately filtering or encoding characters that could be interpreted as HTML or JavaScript. Attackers can craft file names containing malicious payloads such as <script>alert('xss')</script> or other obfuscated script code that gets executed when other users view the uploaded content. The vulnerability specifically leverages the name field of uploaded pictures, which may be displayed directly in HTML output without proper context-based escaping, creating a persistent XSS vector that can affect multiple users who encounter the compromised content.
The operational impact of CVE-2014-6420 extends beyond simple script injection to potentially enable more sophisticated attacks including session hijacking, credential theft, and data exfiltration from victim browsers. When exploited, this vulnerability allows attackers to execute arbitrary JavaScript code in the context of authenticated users, potentially compromising user sessions and enabling unauthorized access to sensitive information. The vulnerability affects the broader web application security landscape by demonstrating how seemingly benign user upload functionality can become a critical attack surface when proper input validation is absent. This flaw particularly impacts content management systems and comment platforms where user-generated content is displayed without adequate sanitization, creating persistent security risks that can remain undetected for extended periods.
Mitigation strategies for CVE-2014-6420 require comprehensive input validation and output encoding practices that align with established security frameworks and best practices. Organizations should implement strict file name sanitization that removes or encodes special characters before processing user uploads, while also ensuring that all user-provided content is properly escaped when rendered in HTML contexts. The remediation approach should include implementing Content Security Policy headers to limit script execution, employing proper input validation libraries, and conducting thorough security testing including dynamic and static analysis of uploaded content handling. Security controls should also incorporate regular monitoring for suspicious file name patterns and implement proper access controls to limit the scope of potential exploitation. This vulnerability serves as a critical reminder of the importance of defense-in-depth strategies that treat all user input as potentially malicious and validate all data flows through application components, aligning with ATT&CK framework techniques for command and control operations that leverage client-side vulnerabilities.