CVE-2024-0011 in PAN-OS
Summary
by MITRE • 02/14/2024
A reflected cross-site scripting (XSS) vulnerability in the Captive Portal feature of Palo Alto Networks PAN-OS software enables execution of malicious JavaScript (in the context of an authenticated Captive Portal user’s browser) if a user clicks on a malicious link, allowing phishing attacks that could lead to credential theft.
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Analysis
by VulDB Data Team • 04/19/2025
This vulnerability resides within the captive portal functionality of Palo Alto Networks PAN-OS software, representing a critical reflected cross-site scripting flaw that undermines the security of authenticated user sessions. The issue manifests when the system fails to properly sanitize user input parameters before reflecting them back to the browser in HTTP responses, creating an avenue for malicious actors to inject executable JavaScript code into the captive portal interface. The vulnerability specifically affects the authentication and session management components that govern how users interact with network access control systems, making it particularly dangerous in enterprise environments where captive portals are commonly deployed for guest access, employee authentication, or network compliance enforcement.
The technical exploitation of this vulnerability requires a sophisticated attack vector that leverages the captive portal's user interaction mechanisms to deliver malicious payloads through crafted URLs or links. When an authenticated user clicks on a malicious link containing specially crafted input parameters, the vulnerable system reflects this input back to the user's browser without proper sanitization, allowing the injected JavaScript code to execute within the context of the user's authenticated session. This creates a persistent threat where attackers can manipulate the captive portal interface to capture user credentials, redirect users to fraudulent websites, or execute additional malicious activities that exploit the elevated privileges associated with authenticated sessions. The vulnerability's classification as reflected XSS (CWE-79) aligns with the standard attack pattern where malicious input is immediately reflected back to the user's browser without proper validation or encoding, making it a prime target for phishing campaigns and credential harvesting operations.
The operational impact of this vulnerability extends beyond simple session hijacking, as it enables sophisticated social engineering attacks that can compromise entire network access control systems. Attackers can craft convincing phishing pages that appear legitimate within the captive portal environment, making it difficult for users to distinguish between authentic and malicious content. The vulnerability's presence in the captive portal feature means that organizations relying on PAN-OS for network access control are exposed to attacks that could bypass traditional security controls, potentially allowing unauthorized access to internal network resources. This threat is particularly severe in environments where captive portals are used for sensitive access control, such as healthcare facilities, financial institutions, or government agencies where credential theft could result in significant data breaches and regulatory compliance violations.
Organizations must implement immediate mitigation strategies to address this vulnerability, beginning with applying the latest PAN-OS software updates that contain patches for the reflected XSS flaw. Network administrators should also consider implementing additional defensive measures such as web application firewalls, input validation rules, and enhanced monitoring of captive portal traffic for suspicious patterns. The vulnerability's exploitation potential aligns with ATT&CK technique T1566 which covers phishing attacks through social engineering, making it essential for security teams to conduct user awareness training and implement multi-factor authentication controls. Additionally, organizations should review their captive portal configurations to ensure that proper input sanitization is enforced and that users are not inadvertently exposed to malicious content through links or redirects that could exploit this vulnerability. The remediation process should include comprehensive testing of patched systems to verify that the XSS vulnerability has been fully resolved while maintaining the functionality of legitimate captive portal operations.