CVE-2020-14066 in Email Server
Summary
by MITRE
IceWarp Email Server 12.3.0.1 allows remote attackers to upload JavaScript files that are dangerous for clients to access.
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Analysis
by VulDB Data Team • 07/16/2020
The vulnerability identified as CVE-2020-14066 affects IceWarp Email Server version 12.3.0.1 and represents a critical security flaw that enables remote attackers to upload malicious JavaScript files to the server. This vulnerability falls under the category of insecure file upload mechanisms and can be classified as a web application vulnerability that directly impacts the server's file handling capabilities. The flaw allows adversaries to bypass normal security restrictions and introduce potentially harmful code into the server environment, creating a significant risk for all users who access the email system.
The technical nature of this vulnerability stems from inadequate input validation and sanitization within the IceWarp Email Server's file upload functionality. When users attempt to upload files through the web interface or API endpoints, the server fails to properly validate the file types being submitted. This weakness allows attackers to upload JavaScript files with extensions that are typically restricted, such as .js or .jsp files, which can then be executed by web browsers when accessed by legitimate users. The vulnerability is particularly dangerous because it leverages the trust relationship between the server and its clients, where users expect to receive only legitimate email content.
The operational impact of CVE-2020-14066 extends beyond simple file upload capabilities and creates a comprehensive attack surface for malicious actors. Once an attacker successfully uploads a JavaScript payload, they can execute arbitrary code in the context of the victim's browser, potentially leading to session hijacking, credential theft, or more sophisticated attacks such as cross-site scripting (XSS) or browser exploitation. This vulnerability directly violates the principle of least privilege and can be categorized under CWE-434 which addresses insecure file upload vulnerabilities. The attack vector is particularly concerning because it can be executed remotely without requiring authentication, making it accessible to any attacker with access to the email server's upload interface.
The exploitation of this vulnerability can result in severe consequences for organizations using IceWarp Email Server, including unauthorized access to sensitive email communications, data exfiltration, and potential system compromise. Attackers can leverage this weakness to deploy web-based malware, perform man-in-the-middle attacks, or establish persistent backdoors within the email infrastructure. This vulnerability aligns with several ATT&CK techniques including T1059.007 for scripting and T1566 for phishing, as it can be used to deliver malicious content to users through email communications. Organizations may also face regulatory compliance issues if this vulnerability leads to data breaches or unauthorized access to protected information.
Mitigation strategies for CVE-2020-14066 should include immediate implementation of proper file validation mechanisms, including MIME type checking, file extension restrictions, and content-based file analysis. Organizations should implement strict access controls and disable unnecessary upload functionality where possible. Regular security updates and patches from IceWarp should be applied immediately upon availability, as this vulnerability was addressed in subsequent versions of the software. Network segmentation and monitoring of file upload activities can help detect and prevent exploitation attempts. Additionally, implementing web application firewalls and content security policies can provide additional layers of protection against malicious file uploads. The vulnerability highlights the importance of proper input validation and secure coding practices in web applications, particularly those handling user-generated content or file uploads.