CVE-2018-13382 — Fortinet FortiOS and FortiProxy Improper Authorization

In brief

Severity · CVSS: High7.5CVSS 3.1, High
EPSS: 82%
CISA KEV: Known exploited, listed since 10 Jan 2022
CERT-FR: No advisory or alert referenced in the catalog
Vendor: Fortinet
Published · Modified: 4 Jun 2019 · 17 Jun 2026
Last verified: 1 Oct 2026 at 09:30 UTC

Summary

An Improper Authorization vulnerability in Fortinet FortiOS 6.0.0 to 6.0.4, 5.6.0 to 5.6.8 and 5.4.1 to 5.4.10 and FortiProxy 2.0.0, 1.2.0 to 1.2.8, 1.1.0 to 1.1.6, 1.0.0 to 1.0.7 under SSL VPN web portal allows an unauthenticated attacker to modify the password of an SSL VPN web portal user via specially crafted HTTP requests

Weakness: CWE-863

Title, description and the vendor's statements are quoted from the CVE record; a vendor's advisory is summarised in Patcharo's words, with a link.

Affected and fixed versions

Per product and release branch, as the vendor's CVE record and official advisory state them. A fixed release is shown only when a document names it: the vendor's, or CERT-FR's for Check Point, with its source.

No precise fixed release is published in the sources Patcharo follows.

Fortinet FortiOS, FortiProxy

Source: CVE-2018-13382

—
Affected versionsFortiOS 6.0.0 to 6.0.4, 5.6.0 to 5.6.8, 5.4.1 to 5.4.10, FortiProxy 2.0.0, 1.2.0 to 1.2.8, 1.1.0 to 1.1.6, 1.0.0 to 1.0.7
First fixed releaseNot published in the sources followed

No precise fixed release is published for this product in the sources Patcharo follows.

Remediation

Vendor guidance

CISA KEV required action

Apply updates per vendor instructions.

CISA due date: 10 Jul 2022

SourceCISA KEV

Vendor advisory

The vendor has published an advisory for this CVE: check it for fixed releases and mitigations.

Sourcehttps://fortiguard.com/advisory/FG-IR-18-389

SourceFortiGuard FG-IR-20-231

Last verified 1 Oct 2026 at 09:30 UTC

Known exploitation

Added to CISA KEV on 10 Jan 2022

Federal remediation due date: 10 Jul 2022

Known use in ransomware campaigns

The CISA required action is shown under Remediation.

82% probability of exploitation in the next 30 days (percentile 100%).

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CERT-FR

No CERT-FR advisory or alert of the last two years references this CVE, for the vendors Patcharo covers.

Timeline

4 Jun 2019Published by the source
10 Jan 2022Added to CISA KEV
10 Jul 2022CISA remediation due date
17 Jun 2026Source record last modified
28 Sept 2026EPSS score computed
1 Oct 2026Last verified by Patcharo

Official sources

Fortinet (CVE record)retrieved 1 Oct 2026 at 09:30 UTC
CISA Known Exploited Vulnerabilitiesretrieved 1 Oct 2026 at 09:28 UTC
NVDretrieved 27 Sept 2026 at 23:44 UTC
FIRST EPSSretrieved 29 Sept 2026 at 03:17 UTC
FortiGuard FG-IR-20-231retrieved 1 Oct 2026 at 09:30 UTC

Vendor advisory

References

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-13382

Fortinet · CISA Known Exploited Vulnerabilities · NVD · FIRST EPSS · FortiGuard FG-IR-20-231

How Patcharo reads this

Affected and fixed releases come from the vendor's structured statements and are matched against exact versions; CVSS from NVD, exploitation from CISA KEV and the vendor's own advisory, probability from FIRST EPSS. Missing data stays Unknown and never becomes Not affected.

Read the methodology Read the guide: FortiOS version numbering: branches, patch releases and the Feature and Mature labels