Netgate pfSense WebGUI Module Authenticated Command Injection Vulnerability [CVE-2018-16055]

CVE Number – CVE-2018-16055

A vulnerability in the WebGUI module of Netgate pfSense could allow an authenticated, remote attacker to inject and execute arbitrary commands on a targeted system.

The vulnerability exists in the dhcp_relinquish_lease() function, as defined in the status_interfaces.php file of the affected software. The dhcp_relinquish_lease() function of the software could pass user-supplied input from the ifdescr and ipv $_POST parameters to a shell without properly escaping variable data. An attacker could exploit this vulnerability by sending a request that submits malicious input to the targeted system. A successful exploit could allow the attacker to execute arbitrary shell commands with root privileges, which could be used to conduct further attacks.

Netgate confirmed the vulnerability and released software updates.

• To exploit this vulnerability, the attacker must have user-level access to the targeted system. This access requirement may reduce the likelihood of a successful exploit.

• Administrators are advised to apply the appropriate updates.

  Administrators are advised to allow only trusted users to have network access.

  Administrators are advised to run both firewall and antivirus applications to minimize the potential of inbound and outbound threats.

  Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.

  Administrators can help protect affected systems from external attacks by using a solid firewall strategy.

  Administrators are advised to monitor affected systems.

• Netgate released a security advisory at the following link: pfSense-SA-18_08.webgui

• Netgate released software updates at the following link: pfSense 2.4.4

Duncan

Duncan is a technology professional with over 20 years experience of working in various IT roles. He has a interest in cyber security, and has a wide range of other skills in radio, electronics and telecommunications.