CVE-2020-18324 in Subrion CMS
Summary
by MITRE • 03/04/2022
Cross Site Scripting (XSS) vulnerability exists in Subrion CMS 4.2.1 via the q parameter in the Kickstart template.
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Analysis
by VulDB Data Team • 03/06/2022
The Cross Site Scripting vulnerability identified as CVE-2020-18324 represents a critical security flaw in Subrion CMS version 4.2.1 that specifically affects the Kickstart template implementation. This vulnerability stems from inadequate input validation and output sanitization mechanisms within the content management system's template processing engine. The q parameter serves as the attack vector, allowing malicious actors to inject arbitrary JavaScript code that executes in the context of other users' browsers when they access affected pages. The vulnerability manifests due to the template engine's failure to properly escape or filter user-supplied input before rendering it within the HTML output, creating an environment where persistent or reflected cross-site scripting attacks can occur.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious payload containing JavaScript code and submits it through the q parameter of the Kickstart template. When the CMS processes this input without proper sanitization, the malicious script gets embedded into the page's HTML structure and subsequently executed in the browsers of unsuspecting users who visit the affected pages. This type of vulnerability falls under CWE-79 which specifically addresses Cross-Site Scripting flaws in web applications, where the weakness allows attackers to inject client-side scripts into web pages viewed by other users. The vulnerability operates at the application layer and can be classified as a reflected XSS attack since the malicious payload is reflected back to the user through the application's response without being stored on the server.
The operational impact of CVE-2020-18324 extends beyond simple data theft or session hijacking, as it enables attackers to perform a wide range of malicious activities including but not limited to cookie theft, session manipulation, redirection to malicious sites, and potential privilege escalation within the CMS environment. Attackers can leverage this vulnerability to gain unauthorized access to user accounts, modify content, or even compromise the entire CMS installation. The vulnerability affects all users of Subrion CMS 4.2.1 who are utilizing the Kickstart template, making it particularly concerning for organizations that have not yet upgraded to patched versions. The attack surface is significant since the q parameter is commonly used for search functionality, making it easily accessible to both legitimate users and malicious actors.
Security mitigation strategies for this vulnerability should include immediate implementation of input validation and output encoding measures within the CMS template processing engine. Organizations must ensure that all user-supplied input is properly sanitized and escaped before being rendered in HTML contexts, following established security practices such as those outlined in the OWASP Top Ten and the ATT&CK framework's web application attack patterns. The most effective remediation involves upgrading to Subrion CMS version 4.2.2 or later, which includes proper input sanitization and output encoding mechanisms. Additionally, implementing Content Security Policy headers, using proper input validation libraries, and conducting regular security audits of template files can help prevent similar vulnerabilities from emerging in the future. Organizations should also consider implementing web application firewalls and monitoring for suspicious parameter usage patterns to detect potential exploitation attempts.