CVE-2014-9439 in Easy File Sharing Web Server
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Easy File Sharing Web Server 6.8 allows remote attackers to inject arbitrary web script or HTML via the username field during registration, which is not properly handled by forum.ghp.
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Analysis
by VulDB Data Team • 01/24/2025
The vulnerability identified as CVE-2014-9439 represents a critical cross-site scripting flaw within Easy File Sharing Web Server version 6.8 that exposes users to significant security risks. This weakness exists in the server's registration process where the username field fails to properly sanitize user input before processing it through the forum.ghp component, creating an avenue for malicious actors to execute arbitrary web scripts or HTML code within the context of other users' browsers. The vulnerability specifically targets the web server's handling of user registration data, particularly focusing on the username parameter that is processed through a forum module without adequate input validation or output encoding mechanisms.
The technical implementation of this XSS vulnerability stems from insufficient input sanitization practices within the server's registration workflow. When users attempt to register with maliciously crafted usernames containing script tags or other HTML elements, the system does not properly escape or filter these inputs before storing or displaying them in the forum. This failure in input validation creates a persistent XSS vector where the malicious code gets executed whenever other users view the affected username in the forum interface. The vulnerability operates at the application layer and can be exploited remotely without requiring any special privileges or authentication, making it particularly dangerous in multi-user environments where forum interactions are common. This type of vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws in software applications.
The operational impact of this vulnerability extends beyond simple script execution, potentially enabling attackers to steal session cookies, perform unauthorized actions on behalf of victims, or redirect users to malicious websites. An attacker could craft a username containing JavaScript that captures user credentials or performs other malicious activities when viewed by other forum participants. The persistent nature of this vulnerability means that once a malicious username is registered, the XSS payload continues to execute for all users who encounter it in the forum interface. This makes the vulnerability particularly dangerous for web servers hosting user-generated content where forum interactions are frequent and users trust the platform's security. The attack surface is further expanded by the fact that this vulnerability affects the registration process, meaning that even legitimate users could inadvertently become victims if they encounter maliciously crafted usernames.
Security mitigations for this vulnerability should focus on implementing robust input validation and output encoding mechanisms throughout the application's data handling pipeline. The most effective approach involves sanitizing all user inputs, particularly those that will be displayed in web contexts, through proper HTML escaping and encoding techniques. Implementing a Content Security Policy (CSP) can provide additional protection by restricting the sources from which scripts can be executed within the browser context. The server should also employ proper input validation that rejects or removes potentially malicious characters from usernames and other user inputs. Organizations should consider implementing automated security scanning tools that can detect similar vulnerabilities in their web applications and ensure that all user-generated content is properly sanitized before being rendered to other users. This vulnerability demonstrates the critical importance of following secure coding practices and adhering to industry standards such as those outlined in the OWASP Top Ten project, which emphasizes the need for proper input validation and output encoding to prevent XSS attacks. The remediation process should also include regular security assessments and code reviews to identify and address similar vulnerabilities that may exist in other parts of the application's functionality.
The vulnerability classifies under ATT&CK technique T1059.007 which covers scripting through web shells and command and control communications. This categorization highlights the potential for this XSS vulnerability to serve as a stepping stone for more sophisticated attacks where attackers might use the initial script execution to establish persistent access or deploy additional malicious payloads. The ease of exploitation and the broad impact make this vulnerability particularly concerning for organizations running web servers that handle user registration and forum functionality. Security teams should implement monitoring solutions that can detect unusual patterns in user registration or forum activity that might indicate exploitation attempts. Regular patching and updating of web server software becomes critical to prevent attackers from leveraging known vulnerabilities like CVE-2014-9439 to compromise user sessions or gain unauthorized access to sensitive data.