Fortinet FortiOS Integer Overflow (FG-IR-21-049)

critical Nessus Plugin ID 156752
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The remote host is affected by a integer overflow vulnerability.


The remote host is running a version of FortiOS prior or equal to 6.0.12, 6.2.x prior or equal to 6.2.9, 6.4.x prior or equal to 6.4.5 or 7.0.0. It is, therefore, affected by an integer overflow vulnerability in FortiOS SSLVPN memory allocator may allow an unauthenticated attacker to corrupt control data on the heap via specifically crafted requests to SSLVPN, resulting in potentially arbitrary code execution.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.


See vendor advisory.

See Also

Plugin Details

Severity: Critical

ID: 156752

File Name: fortios_FG-IR-21-049.nasl

Version: 1.2

Type: local

Family: Firewalls

Published: 1/14/2022

Updated: 1/17/2022

Dependencies: fortinet_version.nbin

Risk Information

CVSS Score Source: CVE-2021-26109


Risk Factor: Medium

Score: 5.9


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: 12/7/2021

Vulnerability Publication Date: 12/7/2021

Reference Information

CVE: CVE-2021-26109

IAVA: 2021-A-0574