Is CVE-2018-13379 being actively exploited?

Yes. CVE-2018-13379 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added on November 3, 2021.

What is the CVSS score for CVE-2018-13379?

CVE-2018-13379 has a CVSS 3.1 base score of 9.1 (CRITICAL).

CVE-2018-13379

CRITICAL · CVSS 9.1CISA KEV: actively exploitedEPSS 100.0%EU EUVD: exploited

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.

Key facts

CVSS score: 9.1 (v3.1)
Severity: CRITICAL
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Weakness (CWE): CWE-22
EPSS score: 100.0% (100th percentile)
In CISA KEV: Yes, added November 3, 2021
In EU EUVD: Yes (EUVD-2018-5323)
Published: June 4, 2019
NVD last modified: June 17, 2026
Status: Analyzed

CISA Known Exploited Vulnerability

Fortinet FortiOS SSL VPN Path Traversal Vulnerability

Added to the KEV catalog on November 3, 2021; federal remediation due May 3, 2022. Known to be used in ransomware campaigns.

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2018-5323 in the EU Vulnerability Database. ENISA flags it as known exploited. Last updated in EUVD on October 21, 2025.

View on the EU Vulnerability Database

Affected products

fortinet / fortios
fortinet / fortiproxy
fortinet / fortiproxy

Certified products that may be affected

3 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

FortiOS 5.6 - Fortinet, Inc. - FIPS 140 3639 - historical
FortiProxy-400E/2000E/4000E - Fortinet, Inc. - FIPS 140 3628 - historical
Fortinet FortiProxy v1.0 - Fortinet, Inc. - Common Criteria 383-4-475 - archived

References

https://fortiguard.com/advisory/FG-IR-18-384(Mitigation, Vendor Advisory)
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-13379(US Government Resource)
https://www.fortiguard.com/psirt/FG-IR-20-233(Vendor Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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