Vulnerability identifier: #VU21375

Vulnerability risk: Medium

CVSSv3.1: 7.1 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:U/RC:C]

CVE-ID: CVE-2019-16701

CWE-ID: CWE-611

Exploitation vector: Network

Exploit availability: Yes

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

Vendor: Rubicon Communications

Description

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to insufficient validation of user-supplied XML input. A remote attacker can pass a specially crafted methodCall XML document to the affected application and execute arbitrary OS commands on the system via the pfsense.exec_php call containing shell metacharacters in a parameter value.

Successful exploitation of the vulnerability may allow an attacker to view contents of arbitrary file on the server or perform network scanning of internal and external infrastructure.

Mitigation
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

pfsense: 2.3.1_1 - 2.4.4_3

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External links
http://packetstormsecurity.com/files/154587/pfSense-2.3.4-2.4.4-p3-Remote-Code-Injection.html
http://github.com/pfsense/pfsense/commits/master
http://hackernews.blog/pfsense-2-3-4-2-4-4-p3-remote-code-injection/#more

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.