Security readout for executives and security teams
Plain-English summary
This flaw lets an unauthenticated internet attacker retrieve system files from vulnerable Fortinet SSL VPN web portals. Because these devices often protect remote access, exposed systems can create business risk beyond the appliance itself, including possible sensitive file disclosure and follow-on access risk.
Executive priority
Treat this as urgent for any internet-facing Fortinet SSL VPN. It is critical severity, requires no authentication, and appears in CISA KEV. Exposure should be confirmed and remediated immediately.
Technical view
CVE-2018-13379 is a CWE-22 path traversal issue in FortiOS and FortiProxy SSL VPN web portal handling. A network attacker with no credentials or user interaction can request crafted resources to download system files. The CVSS 3.1 score is 9.1, with high confidentiality and availability impact.
Likely exposure
Organizations are exposed if affected FortiOS or FortiProxy versions listed in the CVE source bundle run SSL VPN web portal services reachable from untrusted networks.
Exploitation context
CISA KEV includes CVE-2018-13379, so active exploitation is supported by a government source. The supplied bundle does not provide exploit timing, attacker groups, or detailed incident patterns.
Researcher notes
The supplied evidence supports vulnerable product ranges, unauthenticated path traversal, high CVSS impact, and KEV status. It does not include patch-version details or safe test procedures, so validation should rely on version checks, exposure review, logs, and vendor guidance.
Mitigation direction
- Identify FortiOS and FortiProxy SSL VPN web portals running affected versions.
- Review Fortinet advisory FG-IR-18-384 for supported fixed releases and upgrade guidance.
- Prioritize internet-facing SSL VPN appliances before internal-only deployments.
- Check Fortinet PSIRT guidance for any post-compromise or credential-response actions.
- Restrict exposure of SSL VPN portals where business requirements allow.
Validation and detection
- Inventory FortiOS and FortiProxy versions against the affected ranges in the CVE bundle.
- Confirm whether SSL VPN web portal is enabled and externally reachable.
- Review device and perimeter logs for suspicious unauthenticated file access attempts.
- Assess whether sensitive system files may have been exposed before remediation.
- Verify upgraded systems no longer report affected FortiOS or FortiProxy versions.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-22: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2018-13379 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.1 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H3.95.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://fortiguard.com/advisory/FG-IR-18-384CVE reference · x_refsource_CONFIRM
- https://www.fortiguard.com/psirt/FG-IR-20-233CVE reference · x_refsource_CONFIRM
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-13379CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.