huntrule

Fortinet SSL VPN Exploitation Attempt via Path Traversal in Web Requests (CVE-2018-13379)

Alerts on HTTP requests matching a Fortinet SSL VPN traversal-style query indicative of CVE-2018-13379 exploitation.

FreeReviewedSigma · Critical · v5
Category
webserver
Author
Bhabesh Raj (SigmaHQ), DRL 1.1
Published
2020-12-08
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Initial Access

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags web requests targeting Fortinet SSL VPNs that include a specific path traversal pattern combined with a management websession path in the URL query. Such requests matter because they can indicate attempts to reach sensitive internal resources through improperly handled path segments. The detection relies on webserver telemetry capturing the full request URI query string and matching required substrings.

Reporting behind it

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Fortinet SSL VPN Exploitation Attempt via Path Traversal in Web Requests (CVE-2018-13379)
Pivot detection · T1190 · 9 related

Changelog

v5
  1. v5
    Candidate ingested via manual entry.2026-07-31
  2. v4
    Candidate ingested via manual entry.2026-07-31
  3. v3
    Candidate ingested via manual entry.2026-07-31
  4. v2
    Candidate ingested via manual entry.2026-07-31
  5. v1
    No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.