CVE-2011-5047 in pfSense
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in status_rrd_graph.php in pfSense before 2.0.1 allows remote attackers to inject arbitrary web script or HTML via the style parameter.
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Analysis
by VulDB Data Team • 02/13/2019
The CVE-2011-5047 vulnerability represents a critical cross-site scripting flaw discovered in pfSense versions prior to 2.0.1, specifically within the status_rrd_graph.php component of the firewall and router management interface. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is classified as a fundamental web application security weakness that enables attackers to inject malicious scripts into web pages viewed by other users. The affected pfSense software is a popular open-source firewall and router platform that provides comprehensive network security management capabilities for enterprise and small business environments.
The technical exploitation of this vulnerability occurs through manipulation of the style parameter in the status_rrd_graph.php script, which is responsible for generating graphical representations of network status data. When an attacker crafts a malicious payload containing script code within the style parameter and submits it to the vulnerable pfSense installation, the application fails to properly sanitize or escape the input before rendering it in the web interface. This improper input handling creates an opportunity for attackers to execute arbitrary web scripts or HTML code within the context of other users' browser sessions, effectively bypassing the normal security boundaries of the web application.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform a wide range of malicious activities including session hijacking, credential theft, data exfiltration, and redirection to malicious websites. Since pfSense systems are commonly deployed in network infrastructure environments, successful exploitation could compromise the entire network security posture, particularly when administrators access the management interface from potentially compromised workstations. The vulnerability is particularly dangerous because it targets the administrative interface of a critical network security device, potentially allowing attackers to gain unauthorized access to network monitoring data and control functions.
Organizations using pfSense versions prior to 2.0.1 should immediately implement mitigation strategies including applying the official security patch released by pfSense developers, implementing input validation and output encoding measures, and conducting comprehensive security assessments of their network infrastructure. The vulnerability demonstrates the importance of proper input sanitization and output encoding practices as outlined in the OWASP Top Ten security guidelines, particularly addressing the need for robust validation of all user-supplied input. Network administrators should also consider implementing additional security controls such as web application firewalls, regular security audits, and user access controls to minimize the attack surface and reduce the potential impact of similar vulnerabilities in other components of the pfSense platform. The ATT&CK framework categorizes this type of vulnerability under the T1059.007 technique for Scripting, highlighting the need for defensive measures against malicious script execution within web applications.