Vulnerability identifier: #VU31200

Vulnerability risk: High

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-16055

CWE-ID: CWE-78

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
pfsense
Server applications / IDS/IPS systems, Firewalls and proxy servers

Vendor: Rubicon Communications

Description

The vulnerability allows a remote authenticated user to execute arbitrary code.

An authenticated command injection vulnerability exists in status_interfaces.php via dhcp_relinquish_lease() in pfSense before 2.4.4 due to its passing user input from the $_POST parameters "ifdescr" and "ipv" to a shell without escaping the contents of the variables. This allows an authenticated WebGUI user with privileges for the affected page to execute commands in the context of the root user when submitting a request to relinquish a DHCP lease for an interface which is configured to obtain its address via DHCP.

Mitigation
Install update from vendor's website.

Vulnerable software versions

pfsense: 2.4.0 - 2.4.3_1

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External links
http://doddsecurity.com/190/command-injection-on-pfsense-firewalls/
http://www.pfsense.org/security/advisories/pfSense-SA-18_08.webgui.asc

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.