Fortinet FortiOS < 5.6.11, 6.0.x < 6.0.5 SSL VPN Heap Buffer Overflow (FG-IR-18-388)

medium Nessus Plugin ID 125887


The remote host is affected by a heap buffer overflow condition.


The remote host is running a version of FortiOS prior to 5.6.11 or 6.0.x prior to 6.0.5. It is, therefore, affected by a heap buffer overflow condition in the SSL VPN web portal due to improper handling of javascript href data. An unauthenticated, remote attacker can exploit this, by convincing a user to visit a specifically crafted webpage, to cause a denial of service condition.


Upgrade to Fortinet FortiOS version to 5.6.11, 6.0.5, 6.2.0 or later. Alternatively, apply one of the workarounds outlined in the linked advisory

See Also

Plugin Details

Severity: Medium

ID: 125887

File Name: fortios_FG-IR-18-388.nasl

Version: 1.10

Type: local

Family: Firewalls

Published: 6/14/2019

Updated: 9/16/2022

Configuration: Enable paranoid mode

Risk Information


Risk Factor: Medium

Score: 5.1


Risk Factor: Medium

Base Score: 4.3

Temporal Score: 3.7

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

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

CVSS Score Source: CVE-2018-13383


Risk Factor: Medium

Base Score: 6.5

Temporal Score: 6.2

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

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

Vulnerability Information

CPE: cpe:/o:fortinet:fortios

Required KB Items: Host/Fortigate/version, Settings/ParanoidReport

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 4/2/2019

Vulnerability Publication Date: 4/2/2019

CISA Known Exploited Dates: 7/10/2022

Reference Information

CVE: CVE-2018-13383

BID: 108539

IAVA: 0001-A-0004-S