What is CVE-2018-13379?

CVE-2018-13379 is a critical-severity vulnerability in Fortinet Fortios, Fortiproxy, classified under Path Traversal. CVSS score: 9.1/10. Published 2019-06-04.

How severe is CVE-2018-13379?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Is CVE-2018-13379 known to be exploited?

Yes. CVE-2018-13379 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 98 public proof-of-concept repositories are indexed.

Path Traversal in Fortinet Fortios, Fortiproxy

CVE-2018-13379

An Improper Limitation of a Pathname to a Restricted Directory ("Path Traversal") in Fortinet FortiOS 6.0.0 to 6.0.4, 5.6.3 to 5.6.7 and 5.4.6 to 5.4.12 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 download system files via special crafted HTTP resource requests.

Vulnerability class: Path Traversal (Directory Traversal)

Published 2019-06-04 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.

EPSS exploit prediction

EPSS: 1.000 (100.0th percentile), scored 2026-09-30.

Very high probability of exploitation in the next 30 days — among the top 0.1% most-likely-to-be-exploited CVEs. 100th percentile — 100.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Fortinet Fortios, Fortiproxy — versions FortiOS 6.0.0 to 6.0.4, 5.6.3 to 5.6.7 and 5.4.6 to 5.4.12, 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
Fortinet Fortios
Fortinet Fortiproxy — versions 2.0.0

Weakness classification (CWE)

CWE-22 — Path Traversal

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2021-11-03. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2022-05-03.

Required action: Apply updates per vendor instructions.

Known ransomware campaign use: yes.

Public proof-of-concept exploits

References

fortiguard.com/advisory/FG-IR-18-384 (Mitigation, Vendor Advisory)
www.fortiguard.com/psirt/FG-IR-20-233 (Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2018-13379?: CVE-2018-13379 is a critical-severity vulnerability in Fortinet Fortios, Fortiproxy, classified under Path Traversal. CVSS score: 9.1/10. Published 2019-06-04.
How severe is CVE-2018-13379?: Critical severity. CVSS v3 base score is 9.1 out of 10.
Is CVE-2018-13379 known to be exploited?: Yes. CVE-2018-13379 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 98 public proof-of-concept repositories are indexed.