Fortinet FortiWeb - Weak generation of WAF session IDs leads to session fixation (FG-IR-21-214)

critical Nessus Plugin ID 197611


Fortinet Firewall is missing one or more security-related updates.


The version of FortiWeb installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the FG-IR-21-214 advisory.

- A condition for session fixation vulnerability [CWE-384] in the session management of FortiWeb versions 6.4 all versions, 6.3.0 through 6.3.16, 6.2.0 through 6.2.6, 6.1.0 through 6.1.2, 6.0.0 through 6.0.7, 5.9.0 through 5.9.1 may allow a remote, unauthenticated attacker to infer the session identifier of other users and possibly usurp their session. (CVE-2021-42761)

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


Upgrade to FortiWeb version 5.9.2 / 6.0.8 / 6.1.3 / 6.2.7 / 6.3.17 / 7.0.0 or later.

See Also

Plugin Details

Severity: Critical

ID: 197611

File Name: fortiweb_FG-IR-21-214.nasl

Version: 1.0

Type: local

Family: Firewalls

Published: 5/22/2024

Updated: 5/22/2024

Supported Sensors: Nessus

Risk Information


Risk Factor: Medium

Score: 5.9


Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2021-42761


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: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:fortinet:fortiweb

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

Exploit Ease: No known exploits are available

Patch Publication Date: 2/16/2023

Vulnerability Publication Date: 2/16/2023

Reference Information

CVE: CVE-2021-42761