CVE-2018-13379: Fortinet FortiOS SSL VPN Path Traversal Vulnerability
Affects Fortinet FortiOSSource CISA KEV
Exploited in the wild · used in ransomware campaigns · KEV due 3 May 2022 · public exploit available (Metasploit, Exploit-DB) · 99% EPSS : apply the vendor's fix or mitigations to Fortinet FortiOS now.
Data as of 10/24/2026, 20:40:25 UTC
- Exploitation
Actively exploited – in CISA KEV since 11/03/2021
- KEV deadline
- 05/03/2022 US federal agencies must patch by this date; a sensible deadline for everyone else.
- Ransomware
- Used in ransomware campaigns
- EPSS
- 99.9% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Public exploits
- 1 Metasploit module, 2 Exploit-DB entries, a Nuclei detection templatePublic attack or detection tooling exists; see Public exploits below.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HWhat to do
CISA required action
Apply updates per vendor instructions.
Check your hosts for Fortinet FortiOS with threat-finder (opens in a new tab), our free open-source scanner.
Public exploits and detection
Exploit-DB
Nuclei detection templates
Public tooling indexed from Metasploit Framework, Exploit-DB and ProjectDiscovery nuclei-templates. Its existence raises the odds of exploitation; it does not confirm attacks.
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.
Weaknesses
- CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #6OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.