CVE-2025-1748: OpenCart HTML Injection/XSS Vulnerability

CVE-2025-1748 Overview

CVE-2025-1748 is an HTML injection vulnerability affecting OpenCart versions prior to 4.1.0. The flaw resides in the /account/register endpoint, where the parameter name is reflected into the response without proper sanitization. An attacker can craft a malicious URL that, when visited by a victim, causes the browser to render attacker-controlled HTML content within the OpenCart storefront context. The issue is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation).

Critical Impact
Attackers can manipulate the rendered HTML of the victim's browser session, enabling phishing, brand impersonation, and social engineering attacks against OpenCart storefront users.

Affected Products

OpenCart versions prior to 4.1.0
OpenCart storefront /account/register endpoint
Deployments exposing the registration workflow to untrusted users

Discovery Timeline

2025-02-28 - CVE-2025-1748 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-1748

Vulnerability Analysis

The vulnerability stems from insufficient output encoding in the OpenCart account registration workflow. When a request is submitted to /account/register, the server reflects the value of a manipulated parameter name back into the HTML response. Because the application does not neutralize HTML metacharacters before rendering, an attacker can inject arbitrary markup into the page context.

The attack requires user interaction. A victim must click a crafted link, which limits mass exploitation but remains effective in targeted phishing campaigns. Since the injection influences page content within the trusted domain of the OpenCart shop, victims are unlikely to detect the manipulation. The scope is marked as changed because the injected content executes in a context different from the attacker's origin.

Root Cause

The root cause is improper neutralization of user-supplied input placed into HTML output. OpenCart does not sanitize or context-appropriately encode the parameter name used in /account/register before echoing it back to the rendered page. This failure to enforce output encoding results in a reflected HTML injection primitive.

Attack Vector

Exploitation is network-based and requires no authentication. An attacker constructs a URL to the target OpenCart site that includes a manipulated parameter name containing HTML markup. The attacker then delivers the URL through email, chat, or a malicious referrer. When the victim opens the link, the OpenCart server returns a response that includes the injected HTML, which the browser renders as part of the trusted storefront.

The vulnerability does not allow direct script execution in the traditional cross-site scripting sense based on the CVSS impact profile, but it does allow visual defacement, phishing form injection, and credential harvesting attempts staged within the legitimate site.

Refer to the Incibe Security Advisory on OpenCart Vulnerabilities for additional technical context.

Detection Methods for CVE-2025-1748

Indicators of Compromise

Inbound HTTP requests to /account/register containing HTML tags such as <h1>, <form>, <iframe>, or <img> inside parameter names
Web server access logs showing unusually long or URL-encoded parameter names on the registration endpoint
User reports of unexpected content, forms, or branding appearing on the registration page

Detection Strategies

Deploy web application firewall rules that inspect query string parameter names for HTML metacharacters like <, >, and &#
Review OpenCart application logs for anomalous referers or campaign patterns targeting /account/register
Correlate registration page traffic spikes with external phishing indicators or newly registered lookalike domains

Monitoring Recommendations

Enable verbose HTTP request logging for the OpenCart storefront and forward logs to a centralized analytics platform
Alert on requests where parameter names contain non-alphanumeric characters or encoded HTML sequences
Monitor outbound user reports and abuse mailboxes for phishing complaints referencing the storefront domain

How to Mitigate CVE-2025-1748

Immediate Actions Required

Upgrade OpenCart to version 4.1.0 or later where the input handling in /account/register has been corrected
Audit all customizations and third-party extensions that render request parameters into HTML responses
Notify customer-facing teams so they can recognize and triage phishing reports referencing the storefront

Patch Information

OpenCart addressed the vulnerability in version 4.1.0. Administrators should apply the vendor upgrade path and validate that the registration workflow rejects HTML metacharacters in parameter names. Consult the Incibe Security Advisory on OpenCart Vulnerabilities for advisory details and vendor references.

Workarounds

Place a web application firewall in front of the OpenCart storefront and block requests where parameter names contain characters outside [A-Za-z0-9_]
Add reverse proxy rules that strip or reject query strings with malformed parameter names on /account/register
Restrict access to the registration endpoint from suspicious geographies or known malicious referrers until the upgrade is applied

bash

# Example nginx rule to reject HTML metacharacters in query strings on the registration endpoint
location /account/register {
    if ($args ~* "[<>]|%3C|%3E") {
        return 400;
    }
    proxy_pass http://opencart_backend;
}