CVE-2025-0133: Palo Alto PAN-OS GlobalProtect XSS Flaw

CVE-2025-0133 Overview

A reflected cross-site scripting (XSS) vulnerability in the GlobalProtect™ gateway and portal features of Palo Alto Networks PAN-OS® software enables execution of malicious JavaScript in the context of an authenticated Captive Portal user's browser when they click on a specially crafted link. The primary risk is phishing attacks that can lead to credential theft—particularly if you enabled Clientless VPN.

There is no availability impact to GlobalProtect features or GlobalProtect users. Attackers cannot use this vulnerability to tamper with or modify contents or configurations of the GlobalProtect portal or gateways. The integrity impact of this vulnerability is limited to enabling an attacker to create phishing and credential-stealing links that appear to be hosted on the GlobalProtect portal.

For GlobalProtect users with Clientless VPN enabled, there is a limited impact on confidentiality due to inherent risks of Clientless VPN that facilitate credential theft.

Critical Impact

This vulnerability facilitates phishing attacks and credential theft when Clientless VPN is enabled.

Affected Products

• Palo Alto Networks PAN-OS™ GlobalProtect™

Discovery Timeline

• Not Available - Vulnerability discovered by Not Available
• Not Available - Responsible disclosure to Not Available
• Not Available - CVE CVE-2025-0133 assigned
• Not Available - Not Available releases security patch
• 2025-05-14 - CVE CVE-2025-0133 published to NVD
• 2025-05-16 - Last updated in NVD database

Technical Details for CVE-2025-0133

Vulnerability Analysis

This vulnerability is categorized as a reflected cross-site scripting (XSS) issue, which allows attackers to inject malicious scripts into webpages viewed by others. In this case, it specifically targets authenticated users of the GlobalProtect portal.

Root Cause

The root cause of this vulnerability is improper input sanitization in URL parameters processed by the GlobalProtect gateway and portal features.

Attack Vector

Exploitation requires an attacker to craft a malicious URL that, when clicked by an authenticated user, executes JavaScript in the user's browser.

// Example exploitation code (sanitized)
let url = "https://vulnerable-portal.example.com/login?next=\"<script>alert('XSS')</script>";
window.location.href = url;

Detection Methods for CVE-2025-0133

Indicators of Compromise

• Unusual outbound URL requests
• Abnormal client-server interactions
• Presence of anomalous JavaScript execution

Detection Strategies

Leverage intrusion detection systems (IDS) and web application firewalls (WAF) to monitor HTTP traffic for scripting anomalies and exploit patterns typical of XSS attacks.

Monitoring Recommendations

Implement logging mechanisms to capture requests that contain script tags or other suspicious query parameters within URL strings.

How to Mitigate CVE-2025-0133

Immediate Actions Required

• Disable Clientless VPN if not necessary
• Implement strict input validation on all user inputs
• Enforce HTTP response header protections such as Content Security Policy (CSP)

Patch Information

For specific patch details, visit the Palo Alto Networks security advisory: PAN-SA-2025-0005.

Workarounds

Users can mitigate the risk by disabling Clientless VPN and ensuring that all GlobalProtect interactions are carried out over secure communication channels.

# Configuration example to enhance security
set deviceconfig system response-pages management external-url-protection-allowed no