Fortinet FortiOS < 5.6.13 / 6.0 < 6.0.11 Buffer Overflow (FG-IR-20-083)

critical Nessus Plugin ID 141121
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The remote host is affected by an buffer overflow vulnerability.


The remote host is running a version of FortiOS prior to 5.6.13, or 6.x prior to 6.0.11.

It is, therefore, affected by an buffer overflow in the FortiClient NAC daemon that could allow a authenticated remote attacker to crash the FortiClient NAC daemon and theoritcally execute remote code, although no successful proof of concepts currently exist for the RCE.


Upgrade to Fortinet FortiOS version to 5.6.13, 6.0.11, or later.

See Also

Plugin Details

Severity: Critical

ID: 141121

File Name: fortios_FG-IR-20-083.nasl

Version: 1.14

Type: local

Family: Firewalls

Published: 10/2/2020

Updated: 8/12/2021

Dependencies: fortinet_version.nbin

Risk Information

CVSS Score Source: CVE-2020-12820


Risk Factor: High

Score: 7.4


Risk Factor: High

Base Score: 7.5

Temporal Score: 5.5

Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P

Temporal Vector: E:U/RL:OF/RC:C


Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:fortinet:fortios

Required KB Items: Host/Fortigate/version, Host/Fortigate/model

Exploit Ease: No known exploits are available

Patch Publication Date: 9/24/2020

Vulnerability Publication Date: 9/24/2020

Reference Information

CVE: CVE-2020-12820

IAVA: 2020-A-0440-S