CVE-2018-19600 in Rhymix
Summary
by MITRE
Rhymix CMS 1.9.8.1 allows XSS via an index.php?module=admin&act=dispModuleAdminFileBox SVG upload.
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Analysis
by VulDB Data Team • 06/23/2023
The vulnerability CVE-2018-19600 affects Rhymix CMS version 1.9.8.1 and represents a cross-site scripting flaw that occurs during SVG file uploads within the administrative interface. This issue specifically manifests when users attempt to upload SVG files through the module administration section, particularly via the index.php?module=admin&act=dispModuleAdminFileBox endpoint. The vulnerability stems from insufficient input validation and sanitization of uploaded SVG files, allowing malicious actors to inject malicious scripts that execute in the context of other users' browsers. The affected parameter combination within the administrative file upload interface creates a pathway for attackers to bypass normal security controls that would typically prevent script execution in file upload scenarios.
This vulnerability falls under the CWE-79 category of Cross-Site Scripting, which represents one of the most prevalent and dangerous web application security flaws. The attack vector exploits the trust relationship between the web application and its users, enabling the execution of malicious code in the victim's browser context. The specific implementation flaw occurs within the file upload handling mechanism where SVG files are processed without proper sanitization of potentially malicious embedded script tags or JavaScript code within the SVG structure. The vulnerability is particularly concerning because it targets the administrative interface, which typically operates with elevated privileges and access to sensitive system functions.
The operational impact of this vulnerability is significant as it allows authenticated attackers with administrative access or those who can manipulate the upload process to execute arbitrary scripts against other administrators or users who view the maliciously uploaded SVG files. The attack scenario involves uploading a specially crafted SVG file containing malicious JavaScript that executes when the file is displayed in the admin file box interface. This could lead to session hijacking, privilege escalation, data exfiltration, or complete system compromise depending on the attacker's objectives and the permissions of the affected users. The vulnerability directly violates the principle of least privilege and can be leveraged to establish persistent access to the compromised system.
Mitigation strategies for this vulnerability include implementing comprehensive input validation and sanitization of all uploaded file types, particularly SVG files, by removing or escaping potentially dangerous elements and attributes. Organizations should enforce strict file type validation that rejects SVG files containing embedded scripts or executable code, while also implementing Content Security Policy headers to prevent script execution from untrusted sources. The recommended approach involves updating to the latest version of Rhymix CMS where this vulnerability has been patched, implementing proper file upload restrictions that prevent execution of scripts within uploaded files, and conducting regular security assessments of file upload mechanisms. Additionally, implementing web application firewalls and monitoring for suspicious upload activities can provide additional layers of protection against exploitation attempts. The vulnerability highlights the critical importance of validating and sanitizing all user-supplied content, particularly in administrative interfaces where the potential for damage is greatest.