CVE-2025-2870: Clinic Queuing System XSS Vulnerability

CVE-2025-2870 Overview

CVE-2025-2870 is a reflected Cross-Site Scripting (XSS) vulnerability in version 1.0 of the Oretnom23 Clinic Queuing System. The flaw exists in the page parameter of the /patient_side.php endpoint, which reflects unsanitized user input into the HTTP response. An attacker can craft a malicious URL that executes arbitrary JavaScript in a victim's browser session when clicked. The Spanish National Cybersecurity Institute (INCIBE) published the advisory covering this and additional issues in the same application.

Critical Impact
Attackers can execute arbitrary JavaScript in the victim's browser context, enabling session data theft, UI manipulation, and phishing against clinic staff or patients using the queuing system.

Affected Products

Oretnom23 Clinic Queuing System 1.0
Deployments exposing /patient_side.php to untrusted networks
Any downstream forks or repackaged versions of the same PHP codebase

Discovery Timeline

2025-03-28 - CVE-2025-2870 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-2870

Vulnerability Analysis

The vulnerability is a reflected XSS issue classified under [CWE-79], Improper Neutralization of Input During Web Page Generation. The patient_side.php script accepts a page query parameter and renders its value into the returned HTML without adequate output encoding or input validation. Because the payload is reflected in the immediate response, exploitation depends on delivering a crafted link to an authenticated user. The attack requires low privileges and user interaction, and it affects confidentiality and integrity of the browser session rather than the underlying server. Successful exploitation runs in the victim's browser origin, giving attackers access to any data or actions the victim can perform within the application.

Root Cause

The root cause is missing contextual output encoding on the page request parameter before it is embedded in the rendered HTML of /patient_side.php. The application does not apply PHP escaping functions such as htmlspecialchars() or a template engine that auto-escapes untrusted values. Combined with the absence of a restrictive Content Security Policy, this allows browser-side execution of injected script content.

Attack Vector

Exploitation is network-based and does not require attacker-controlled infrastructure beyond a hosted payload or crafted URL. An attacker sends a link containing a malicious page value to a clinic staff member or patient through email, chat, or a compromised page. When the victim opens the link while authenticated to the Clinic Queuing System, the injected JavaScript executes in their browser and can read cookies, submit forms, or pivot to internal application actions. See the INCIBE Security Notice on Vulnerabilities for the coordinated advisory covering this issue.

No verified public proof-of-concept code is available for this CVE. Refer to the INCIBE advisory for technical details of the reflected parameter and affected endpoint.

Detection Methods for CVE-2025-2870

Indicators of Compromise

HTTP GET requests to /patient_side.php containing page= values with characters such as <, >, %3C, %3E, script, onerror, or javascript:.
Web server access logs showing unusually long or URL-encoded page parameter values originating from external referrers.
Browser console errors or unexpected outbound requests from clinic workstations after users open emailed links.

Detection Strategies

Deploy a Web Application Firewall (WAF) rule set that inspects the page query parameter on /patient_side.php for HTML tags, event handlers, and JavaScript URI schemes.
Enable server-side request logging with full query strings and correlate with authenticated session identifiers to identify targeted users.
Use browser-side telemetry or CSP report-uri endpoints to capture script-src violations that indicate reflected injection attempts.

Monitoring Recommendations

Monitor referrer headers on /patient_side.php for external domains delivering encoded XSS payloads.
Alert on repeated 200 responses to /patient_side.php with parameter values exceeding a defined length threshold.
Track user reports of unexpected redirects, popups, or credential prompts within the Clinic Queuing System.

How to Mitigate CVE-2025-2870

Immediate Actions Required

Restrict access to the Clinic Queuing System to trusted internal networks or VPN users until a vendor fix is available.
Deploy WAF signatures that block XSS payload patterns in the page parameter of /patient_side.php.
Instruct clinic staff and patients not to click on unsolicited links referencing the queuing system.

Patch Information

No vendor advisory or official patch has been published in the NVD entry at the time of writing. Consult the INCIBE Security Notice on Vulnerabilities for updates and contact the project maintainer for a fixed release before returning the application to production.

Workarounds

Apply server-side input validation and output encoding on the page parameter using htmlspecialchars($value, ENT_QUOTES, 'UTF-8') before rendering.
Deploy a strict Content Security Policy that disallows inline scripts and restricts script-src to trusted origins.
Set the HttpOnly and Secure flags on session cookies to limit impact if a payload executes.

bash

# Example nginx configuration to block obvious XSS payloads on the vulnerable endpoint
location /patient_side.php {
    if ($arg_page ~* "(<|%3C)script|onerror=|javascript:") {
        return 403;
    }
    add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'" always;
    add_header X-XSS-Protection "1; mode=block" always;
}