CVE-2014-4688 in pfSense
Summary
by MITRE
pfSense before 2.1.4 allows remote authenticated users to execute arbitrary commands via (1) the hostname value to diag_dns.php in a Create Alias action, (2) the smartmonemail value to diag_smart.php, or (3) the database value to status_rrd_graph_img.php.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 03/22/2025
The vulnerability identified as CVE-2014-4688 represents a critical command injection flaw affecting pfSense versions prior to 2.1.4. This security weakness resides in the web-based administrative interface of pfSense, a widely deployed open-source firewall and router platform that serves millions of network devices globally. The vulnerability manifests through three distinct attack vectors within the pfSense web interface, each presenting unique opportunities for malicious actors to execute arbitrary commands on the underlying system.
The technical exploitation occurs through improper input validation and sanitization within three specific PHP scripts. In diag_dns.php, when users create aliases through the web interface, the hostname parameter is not adequately sanitized before being processed, allowing attackers to inject malicious command sequences that get executed on the server. Similarly, diag_smart.php contains a vulnerability where the smartmonemail parameter fails to properly validate user input, while status_rrd_graph_img.php suffers from insecure handling of the database parameter. These flaws stem from the application's failure to properly escape or filter user-supplied data before incorporating it into system commands or database queries, creating pathways for command injection attacks.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as authenticated users can leverage these command injection flaws to gain complete control over the pfSense appliance. Attackers can execute arbitrary system commands with the privileges of the web server process, potentially leading to full system compromise, data exfiltration, network reconnaissance, and lateral movement within the network environment. Given that pfSense appliances often serve as critical network gateways and firewall components, successful exploitation can result in widespread network disruption, unauthorized access to protected resources, and complete compromise of network security posture. The authenticated nature of the attack means that attackers need only valid user credentials, which are often obtained through social engineering, credential reuse, or other initial compromise techniques.
Mitigation strategies for CVE-2014-4688 center on immediate patching of pfSense installations to version 2.1.4 or later, which contains the necessary input validation and sanitization fixes. Organizations should also implement network segmentation to limit access to pfSense administrative interfaces, enforce strong authentication mechanisms including multi-factor authentication, and regularly audit user permissions to ensure least privilege access. Security monitoring should include detection of unusual command execution patterns and unauthorized administrative access attempts. This vulnerability aligns with CWE-77 and CWE-89, representing command injection and SQL injection weaknesses respectively, and maps to ATT&CK techniques including privilege escalation and command and control through the execution of malicious code on compromised systems. The remediation process should also include comprehensive security testing of web applications and regular vulnerability assessments to identify similar input validation weaknesses in other network infrastructure components.