CVE-2018-9177 in Twonky Server
Summary
by MITRE
Twonky Server before 8.5.1 has XSS via a folder name on the Shared Folders screen.
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Analysis
by VulDB Data Team • 02/17/2020
The vulnerability identified as CVE-2018-9177 affects Twonky Server versions prior to 8.5.1 and represents a cross-site scripting flaw that manifests through folder names displayed on the Shared Folders screen. This issue falls under the category of client-side injection vulnerabilities where malicious input can be executed within the context of a user's browser session. The vulnerability stems from insufficient input validation and output encoding mechanisms within the web interface, specifically when rendering folder names that may contain malicious script content. The affected Twonky Server web application fails to properly sanitize user-provided folder names before displaying them in the browser, creating an opportunity for attackers to inject malicious JavaScript code that executes in the context of other users' sessions.
The technical exploitation of this vulnerability occurs when an attacker creates or modifies a folder name containing malicious script content such as javascript:alert(1) or other XSS payloads. When other users navigate to the Shared Folders screen and view the malicious folder name, the embedded script executes in their browser context, potentially leading to session hijacking, credential theft, or redirection to malicious sites. This type of vulnerability is categorized as CWE-79 - Cross-site Scripting and aligns with ATT&CK technique T1566.001 - Phishing via Social Media within the initial access phase of the attack lifecycle. The flaw exists because the application does not properly encode special characters in folder names before rendering them in HTML output, allowing attackers to inject HTML tags and JavaScript code directly into the web interface.
The operational impact of this vulnerability extends beyond simple script execution as it can enable attackers to establish persistent access to the Twonky Server environment. An attacker could craft folder names that redirect users to phishing sites, steal session cookies, or even execute more sophisticated attacks such as credential harvesting or browser exploitation techniques. The vulnerability affects the web-based management interface of Twonky Server, which is typically accessible to authorized users within the network, making it a significant concern for organizations that rely on this media server software for home or enterprise media sharing. The risk is amplified when considering that media servers often contain personal or sensitive content, and attackers could exploit this vulnerability to gain unauthorized access to media libraries or perform reconnaissance on the server's configuration.
Mitigation strategies for CVE-2018-9177 should focus on implementing proper input validation and output encoding mechanisms within the Twonky Server web interface. Organizations should immediately upgrade to Twonky Server version 8.5.1 or later, which contains the necessary patches to address the XSS vulnerability. Additionally, administrators should implement proper input sanitization for all user-provided content, including folder names, by implementing strict character filtering and HTML encoding. Network segmentation and access controls should be enforced to limit exposure of the Twonky Server web interface to trusted users only. The implementation of Content Security Policy headers can provide an additional layer of protection against XSS attacks by restricting script execution within the browser context. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in the web application, as this type of flaw can indicate broader issues with input validation and output encoding practices that may affect other components of the application.