pfSense before 2.3 allows remote authenticated users to execute arbitrary OS commands via a '|' character in the status_rrd_graph_img.php graph parameter, related to _rrd_graph_img.php.
https://www.exploit-db.com/exploits/39709/
https://www.pfsense.org/security/advisories/pfSense-SA-16_01.webgui.asc
https://www.rapid7.com/db/modules/exploit/unix/http/pfsense_graph_injection_exec
https://www.security-assessment.com/files/documents/advisory/pfsenseAdvisory.pdf
Source: MITRE
Published: 2018-01-22
Updated: 2018-02-09
Type: CWE-78
Base Score: 9
Vector: AV:N/AC:L/Au:S/C:C/I:C/A:C
Impact Score: 10
Exploitability Score: 8
Severity: HIGH
Base Score: 8.8
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 2.8
Severity: HIGH