CVE-2018-13379

KEVRansomware UseFortinet FortiOS SSL VPN Path Traversal Vulnerability

Description

Fortinet FortiOS SSL VPN web portal contains a path traversal vulnerability that may allow an unauthenticated attacker to download FortiOS system files through specially crafted HTTP resource requests.

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.

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

PublishedJun 4, 2019

Last modifiedJun 17, 2026

Added to KEVNov 3, 2021

Remediation dueMay 3, 2022

References

fortiguard.com/advisory/FG-IR-18-384MitigationVendor Advisory
fortiguard.com/psirt/FG-IR-20-233Vendor Advisory
cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-13379US Government Resource

0 recent articles mention this CVE

Risk assessment · Critical

Actively exploited and used by ransomware crews. Patch immediately.

Exploitation: Confirmed in the wild (CISA KEV)
Federal remediation deadline: Overdue by 1637 days
Ransomware: Used in known ransomware campaigns
CVSS: 9.1 CRITICAL
EPSS (30-day exploit probability): 100.0% · top 1% of all CVEs
Weakness: CWE-22
Attack vector: Network, remotely reachable
Preconditions: No privileges and no user interaction

Recommended actions

1.Apply updates per vendor instructions.
2.Treat as emergency change: patch or isolate internet-facing instances first.
3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
5.Verify offline/immutable backups and segment the affected systems. This flaw is used for ransomware initial access.

Assessment is derived automatically from the live signals above; verify against your own asset inventory.