CVE-2018-15563 in Subrion CMS
Summary
by MITRE
_core/admin/pages/add/ in Subrion CMS 4.2.1 has XSS via the titles[en] parameter.
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Analysis
by VulDB Data Team • 06/30/2020
The vulnerability identified as CVE-2018-15563 represents a cross-site scripting flaw within Subrion CMS version 4.2.1 that specifically targets the administrative pages functionality. This issue resides in the core/admin/pages/add/ endpoint where user input is not properly sanitized before being processed and stored within the system. The vulnerability manifests when an attacker can inject malicious script code through the titles[en] parameter, which is typically used to define page titles in the English language within the content management system's administrative interface. This particular attack vector demonstrates a classic lack of input validation and output encoding that allows malicious payloads to persist within the application's database and execute when legitimate users access the affected pages.
The technical exploitation of this vulnerability occurs through the manipulation of the titles[en] parameter during the page creation process within the administrative panel. When an attacker submits crafted malicious input containing script tags or other executable code through this parameter, the system fails to properly sanitize or encode the input before storing it in the database. The vulnerability is classified as a reflected cross-site scripting issue according to CWE-79, which specifically addresses the improper handling of user-controllable input that can lead to malicious script execution in web browsers. This flaw operates under the principle that the application does not adequately validate or escape user-supplied data before it is rendered back to users, creating an environment where attacker-controlled scripts can execute in the context of other users' browsers.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with the ability to perform various malicious activities within the compromised environment. An attacker could potentially steal session cookies, redirect users to malicious websites, modify page content, or even escalate privileges within the CMS administration interface. The severity of this vulnerability is particularly concerning because it affects the administrative functionality of the CMS, potentially allowing unauthorized individuals to gain elevated access to the system. According to ATT&CK framework, this vulnerability maps to T1059.007 for scripting and T1548.001 for abuse of privileges, as it enables attackers to execute malicious code and potentially escalate their access level. The vulnerability also aligns with T1190 for exploitation of remote services and T1071.001 for application layer protocol usage, as it leverages the web application's administrative interface to execute malicious payloads.
Mitigation strategies for CVE-2018-15563 should focus on implementing comprehensive input validation and output encoding mechanisms throughout the Subrion CMS application. The immediate solution involves applying the official security patch released by Subrion CMS developers to address this specific vulnerability. Organizations should also implement proper parameter sanitization that removes or encodes potentially dangerous characters such as angle brackets, quotes, and script tags from all user-supplied input before processing. The implementation of Content Security Policy headers can provide an additional layer of protection by restricting the sources from which scripts can be loaded and executed. Regular security audits should be conducted to identify similar input validation weaknesses in other parts of the application, as this vulnerability represents a broader class of issues that can affect web applications. Organizations should also consider implementing web application firewalls that can detect and block malicious payloads attempting to exploit similar cross-site scripting vulnerabilities in their CMS infrastructure. The vulnerability serves as a reminder of the critical importance of proper input validation and output encoding in preventing XSS attacks, particularly within administrative interfaces where the potential for privilege escalation exists.