CVE-2025-59715: SMSEagle Reflected XSS Vulnerability

CVE-2025-59715 Overview

CVE-2025-59715 is a reflected cross-site scripting (XSS) vulnerability in SMSEagle versions prior to 6.11. The flaw allows attackers to inject malicious JavaScript through the username field or contact phone number field. When a victim renders the crafted response, the browser executes the attacker-controlled script in the context of the SMSEagle application. The vulnerability is classified as [CWE-79] Improper Neutralization of Input During Web Page Generation.

Critical Impact
Successful exploitation enables session hijacking, credential theft, and unauthorized actions within the SMSEagle web interface. Exploitation requires user interaction and low-privileged authentication.

Affected Products

SMSEagle software versions prior to 6.11
SMSEagle hardware SMS gateway appliances running vulnerable firmware
Web management interface components handling user and contact input

Discovery Timeline

2025-09-19 - CVE-2025-59715 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-59715

Vulnerability Analysis

The vulnerability resides in how the SMSEagle web application processes user-supplied data before rendering it back to the browser. The username field and contact phone number field accept input without sufficient output encoding. An attacker who supplies HTML or JavaScript payloads in these fields causes the browser to execute the payload when the response is reflected.

Because the CVSS scope is changed, injected script executes in a security context beyond the vulnerable component. This enables cross-boundary impact against administrative sessions and connected users of the SMS gateway.

Root Cause

The root cause is missing or insufficient output encoding when rendering user-controlled values into HTML responses. The application trusts input submitted to authentication and contact-management endpoints. Without contextual escaping, script content survives into the DOM and executes.

Attack Vector

An attacker delivers a crafted URL or form submission containing a JavaScript payload in the username or contact phone number parameter. A logged-in operator who clicks the link or views the poisoned page triggers execution of the payload. The attacker can then exfiltrate session cookies, submit unauthorized SMS messages, or pivot to further actions available to the victim.

The vulnerability manifests in web pages that echo user input without encoding. Refer to the SMSEagle Security Advisory for vendor technical details.

Detection Methods for CVE-2025-59715

Indicators of Compromise

HTTP request or referrer logs containing <script>, onerror=, onload=, or URL-encoded equivalents in username or contact phone number parameters
Unexpected outbound requests from operator browsers to attacker-controlled domains following SMSEagle interface access
Anomalous SMS dispatch events or contact modifications originating from authenticated operator sessions

Detection Strategies

Inspect SMSEagle web server access logs for reflected input patterns containing HTML tags or JavaScript event handlers
Deploy a web application firewall rule that flags XSS payload signatures targeting /login and contact management endpoints
Correlate operator session activity with unusual client-side navigation to detect payload execution

Monitoring Recommendations

Enable verbose HTTP request logging on the SMSEagle appliance and forward events to a centralized log platform
Alert on repeated 200-response requests containing script metacharacters in authentication or contact fields
Monitor for phishing lures directing operators to crafted SMSEagle URLs

How to Mitigate CVE-2025-59715

Immediate Actions Required

Upgrade SMSEagle to version 6.11 or later as documented in the vendor advisory
Restrict SMSEagle web interface exposure to trusted management networks only
Rotate operator credentials and invalidate active sessions after patching
Train operators to avoid clicking unverified links referencing the SMSEagle interface

Patch Information

SMSEagle resolved the reflected XSS in software release 6.11. The vendor advisory is available at SMSEagle Security Advisory - Resolved XSS in SMSEagle software 6.11. Apply the update through the standard SMSEagle software upgrade procedure.

Workarounds

Place the SMSEagle management interface behind a reverse proxy that enforces a strict Content Security Policy
Configure the web server to set X-XSS-Protection and Content-Security-Policy response headers blocking inline script execution
Limit access to the administration interface via IP allowlisting until the patch is applied

bash

# Example nginx reverse proxy hardening for SMSEagle management interface
server {
    listen 443 ssl;
    server_name smseagle.internal.example;

    add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-Frame-Options "DENY" always;
    add_header Referrer-Policy "no-referrer" always;

    allow 10.0.0.0/24;   # management network
    deny  all;

    location / {
        proxy_pass https://smseagle-backend;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}