CVE-2019-25277: FaceSentry Access Control XSS Vulnerability

CVE-2019-25277 Overview

FaceSentry Access Control System version 6.4.8 contains a cross-site scripting (XSS) vulnerability in the msg parameter of the pluginInstall.php endpoint. This vulnerability allows attackers to inject malicious scripts through unvalidated user input, enabling execution of arbitrary JavaScript in victim browsers. Successful exploitation can lead to theft of authentication credentials, session hijacking, and phishing attacks targeting users of the access control system.

Critical Impact
Attackers can steal authentication credentials and conduct phishing attacks by injecting malicious JavaScript through the unvalidated msg parameter, potentially compromising physical access control systems.

Affected Products

FaceSentry Access Control System 6.4.8

Discovery Timeline

2026-01-08 - CVE-2019-25277 published to NVD
2026-01-08 - Last updated in NVD database

Technical Details for CVE-2019-25277

Vulnerability Analysis

This vulnerability is classified as a Cross-Site Scripting (XSS) flaw (CWE-79) affecting the FaceSentry Access Control System. The pluginInstall.php script fails to properly sanitize or encode the msg parameter before reflecting it back to the user's browser. This allows an attacker to craft a malicious URL containing JavaScript payloads that execute within the context of a victim's authenticated session.

When exploited, this vulnerability enables attackers to perform actions on behalf of authenticated users, steal session cookies, capture keystrokes, or redirect users to malicious phishing pages. Given that FaceSentry is an access control system, successful exploitation could have significant security implications for physical security infrastructure.

Root Cause

The root cause of this vulnerability is improper input validation and insufficient output encoding in the pluginInstall.php script. The msg parameter accepts user-supplied input without proper sanitization or HTML entity encoding before being rendered in the response. This violates the fundamental security principle of never trusting user input and always encoding output in the appropriate context.

Attack Vector

The attack vector for this vulnerability is network-based and requires user interaction. An attacker crafts a malicious URL containing JavaScript code in the msg parameter and tricks an authenticated user into clicking the link. This can be accomplished through phishing emails, social engineering, or embedding the malicious link in websites the target user is likely to visit. When the victim accesses the crafted URL, the malicious script executes within their browser session with full access to the FaceSentry web application context.

The vulnerability details and proof-of-concept information are available through the Zero Science Vulnerability Report and Packet Storm Security.

Detection Methods for CVE-2019-25277

Indicators of Compromise

Suspicious requests to pluginInstall.php containing script tags or JavaScript event handlers in the msg parameter
HTTP access logs showing URL-encoded payloads such as %3Cscript%3E or javascript: in query strings targeting the affected endpoint
User reports of unexpected browser behavior or redirects when accessing FaceSentry interface

Detection Strategies

Implement Web Application Firewall (WAF) rules to detect and block common XSS payloads in HTTP requests
Configure intrusion detection systems to alert on requests containing script injection patterns targeting pluginInstall.php
Review HTTP access logs for suspicious patterns in the msg parameter including angle brackets, script tags, and event handlers

Monitoring Recommendations

Enable detailed logging for the FaceSentry Access Control System web interface
Monitor for anomalous authentication patterns that may indicate session hijacking
Configure real-time alerting for any requests to pluginInstall.php with non-standard msg parameter values

How to Mitigate CVE-2019-25277

Immediate Actions Required

Restrict network access to the FaceSentry web interface to trusted IP addresses only
Implement a Web Application Firewall (WAF) with XSS protection rules in front of the FaceSentry system
Review user activity logs for any signs of exploitation or unauthorized access
Consider disabling or restricting access to pluginInstall.php if the functionality is not required

Patch Information

No vendor patch information is available in the current CVE data. Organizations should contact the FaceSentry vendor directly for updated firmware or software that addresses this vulnerability. Additional technical details can be found in the IBM X-Force Vulnerability Database and CXSecurity Vulnerability Report.

Workarounds

Deploy a reverse proxy or WAF configured to sanitize or block requests containing potentially malicious content in the msg parameter
Implement Content Security Policy (CSP) headers to restrict inline script execution if the web server configuration allows
Limit access to administrative interfaces through network segmentation and IP whitelisting
Enable HTTP-only and Secure flags on all session cookies to reduce the impact of potential session theft

bash

# Example WAF rule to block XSS attempts (ModSecurity format)
SecRule ARGS:msg "@rx (?i)<script|javascript:|on\w+\s*=" \
    "id:100001,phase:2,deny,status:403,msg:'Potential XSS attack blocked on msg parameter'"