CVE-2024-1528: CMS Made Simple XSS Vulnerability

CVE-2024-1528 Overview

CVE-2024-1528 is a reflected Cross-Site Scripting (XSS) vulnerability [CWE-79] affecting CMS Made Simple version 2.2.14. The flaw resides in /admin/moduleinterface.php, where multiple parameters accept user-controlled input without sufficient output encoding. A remote attacker can craft a malicious JavaScript payload and deliver it to an authenticated administrator. When the target loads the crafted request, the script executes in the context of the admin session and can partially hijack browser state, including cookies and in-page actions.

Critical Impact
Successful exploitation lets an attacker execute arbitrary JavaScript in an authenticated administrator's browser, enabling session data theft and unauthorized administrative actions within the CMS.

Affected Products

CMS Made Simple 2.2.14
Administrative interface component /admin/moduleinterface.php
Deployments exposing the admin console to untrusted networks

Discovery Timeline

2024-03-12 - CVE-2024-1528 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-1528

Vulnerability Analysis

The vulnerability is a classic reflected XSS in the CMS Made Simple administrative interface. The moduleinterface.php endpoint accepts multiple request parameters and reflects their values into rendered HTML without applying context-appropriate encoding. Because the reflected content is treated as markup rather than data, attacker-supplied <script> tags or event handler attributes execute in the victim's browser. Exploitation requires an authenticated administrator to load an attacker-crafted URL, so social engineering or a delivery channel such as a phishing message is a prerequisite. Once executed, the payload runs with the privileges of the target session and can read DOM content, manipulate the admin interface, and issue authenticated requests.

Root Cause

The root cause is missing or incomplete output encoding on user-controllable parameters processed by /admin/moduleinterface.php. Input passed through the URL query string flows into HTML response bodies without being escaped for the HTML or attribute context, violating the neutralization requirement described by CWE-79.

Attack Vector

The attack is network-based and requires user interaction. An attacker constructs a URL targeting the vulnerable admin endpoint with a JavaScript payload embedded in an affected parameter. The attacker then delivers this URL to an authenticated administrator through email, chat, or a link on an external site. When the administrator visits the URL while logged into the CMS, the browser renders the reflected payload and executes the attacker's script within the CMS origin.

No verified public proof-of-concept code is available for this CVE. Refer to the INCIBE Security Notice for the coordinated advisory details.

Detection Methods for CVE-2024-1528

Indicators of Compromise

Web server access logs containing requests to /admin/moduleinterface.php with parameter values that include <script>, onerror=, javascript:, or URL-encoded equivalents such as %3Cscript%3E.
Referrer headers on admin requests pointing to external, untrusted domains.
Unexpected outbound requests from administrator browsers to attacker-controlled hosts shortly after visiting the admin interface.

Detection Strategies

Deploy a web application firewall (WAF) rule that inspects query parameters submitted to /admin/moduleinterface.php for HTML control characters and known XSS signatures.
Enable server-side logging of full request URIs on the CMS host and alert on admin endpoint requests containing script-like tokens.
Correlate admin session activity with anomalous DOM-initiated requests observed in browser telemetry or proxy logs.

Monitoring Recommendations

Monitor authentication logs for administrator sessions that perform sensitive actions immediately after loading crafted URLs.
Track Content Security Policy (CSP) violation reports if CSP is enabled on the CMS.
Review referer and user-agent patterns for admin traffic to identify likely phishing delivery of malicious links.

How to Mitigate CVE-2024-1528

Immediate Actions Required

Upgrade CMS Made Simple to a release later than 2.2.14 that addresses the reflected XSS in moduleinterface.php.
Restrict access to the /admin/ path to trusted IP ranges or a VPN until patching is complete.
Instruct administrators to avoid clicking untrusted links while authenticated to the CMS.

Patch Information

Consult the INCIBE Security Notice and the CMS Made Simple vendor site for the current fixed release. Apply the upstream update to any instance running version 2.2.14 and validate that the admin interface no longer reflects unencoded input.

Workarounds

Deploy a WAF rule that blocks or sanitizes requests to /admin/moduleinterface.php containing HTML metacharacters in query parameters.
Enforce a strict Content Security Policy that disallows inline scripts on admin pages to reduce payload execution success.
Require administrators to use isolated browser profiles or dedicated management workstations that do not browse arbitrary web content.

bash

# Example nginx snippet restricting admin access to a trusted subnet
location /admin/ {
    allow 10.0.0.0/24;
    deny all;
}