CVE-2025-4326: MRCMS XSS Vulnerability in Add Fragment

CVE-2025-4326 Overview

CVE-2025-4326 is a cross-site scripting (XSS) vulnerability in MRCMS version 3.1.2. The flaw resides in the /admin/chip/add.do endpoint of the Add Fragment Page component. An authenticated attacker can inject arbitrary script content, which executes in the browser context of users who view the affected administrative page.

The vulnerability has been publicly disclosed, increasing exposure for unpatched deployments. It is tracked under CWE-79: Improper Neutralization of Input During Web Page Generation.

Critical Impact
Attackers with high-privilege access can inject persistent scripts into the MRCMS admin interface, enabling session theft, credential capture, and administrative action hijacking against other operators.

Affected Products

MRCMS 3.1.2
Component: Add Fragment Page (/admin/chip/add.do)
Deployments exposing the admin console to untrusted networks

Discovery Timeline

2025-05-06 - CVE-2025-4326 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-4326

Vulnerability Analysis

The vulnerability affects the Add Fragment Page handler at /admin/chip/add.do in MRCMS 3.1.2. User-supplied input processed by this endpoint is reflected or stored without proper HTML entity encoding or input sanitization. When an administrator renders a page that includes the attacker-controlled fragment data, the browser interprets the injected payload as executable script.

Exploitation requires an authenticated session with privileges to submit fragments. User interaction is also needed to trigger the payload. The impact is limited to the integrity of client-side content rendered within the admin interface.

Root Cause

The root cause is improper neutralization of input during web page generation [CWE-79]. The add.do handler does not escape metacharacters such as <, >, and " before echoing fragment field values into HTML output. Any script tags, event handlers, or JavaScript URIs supplied by the attacker remain intact in the rendered DOM.

Attack Vector

An attacker with valid administrative credentials submits a crafted fragment through the /admin/chip/add.do form. The payload is stored and later rendered when another operator views the fragment management page. The injected script executes under the victim's session, allowing cookie theft, forced actions through the admin API, or pivoting to further compromise of the content management system.

Technical details and the public proof-of-concept are available in the GitHub issue report and the VulDB entry #307427.

Detection Methods for CVE-2025-4326

Indicators of Compromise

HTTP POST requests to /admin/chip/add.do containing <script>, onerror=, onload=, or javascript: substrings in form parameters
Unexpected outbound requests from admin browsers to attacker-controlled domains following fragment page visits
New or modified fragment records in the MRCMS database containing raw HTML or JavaScript syntax

Detection Strategies

Deploy web application firewall (WAF) rules that flag XSS payload patterns targeting MRCMS admin endpoints
Review web server access logs for POST requests to /admin/chip/add.do originating from unusual source addresses or user accounts
Correlate admin session activity with outbound DNS and HTTP traffic to identify beaconing from compromised browser sessions

Monitoring Recommendations

Enable detailed request body logging on the MRCMS admin interface for forensic review
Alert on administrator accounts creating fragment entries outside normal business hours or in high volumes
Monitor browser-side Content Security Policy (CSP) violation reports if CSP is deployed in report-only mode

How to Mitigate CVE-2025-4326

Immediate Actions Required

Restrict access to the MRCMS admin console using network ACLs, VPN, or IP allowlisting until a patch is applied
Audit the fragment table for stored payloads containing script tags or JavaScript event handlers and remove malicious entries
Rotate administrator credentials and invalidate active sessions if suspicious fragment submissions are identified

Patch Information

No vendor patch has been published in the referenced advisories at the time of writing. Monitor the MRCMS project repository and VulDB entries for remediation updates. Organizations running MRCMS 3.1.2 should plan to upgrade as soon as a fixed release becomes available.

Workarounds

Apply a reverse proxy or WAF rule that strips or escapes HTML metacharacters in requests to /admin/chip/add.do
Enforce a strict Content Security Policy on admin pages to block inline script execution and external script sources
Limit fragment creation privileges to a minimal set of trusted administrators and require multi-factor authentication for admin logins

bash

# Example NGINX rule to block common XSS payloads targeting the vulnerable endpoint
location /admin/chip/add.do {
    if ($request_body ~* "(<script|onerror=|onload=|javascript:)") {
        return 403;
    }
    proxy_pass http://mrcms_backend;
}