CVE-2019-5591: Fortinet FortiOS Default Configuration Vulnerability
Reference page built from the source records below, each shown as its source publishes it. Dataset version ref-9887a903b86f, updated 2026-11-02T23:39:54.475Z.
CISA Known Exploited Vulnerabilities
- Name
- Fortinet FortiOS Default Configuration Vulnerability
- Vendor
- Fortinet
- Product
- FortiOS
- Added to the catalog
- 2021-11-03
- Due date for US federal agencies
- 2022-05-03
- Weaknesses
- CWE-306
- Catalog version
- 2026.10.30
Fortinet FortiOS contains a default configuration vulnerability that may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the Lightweight Directory Access Protocol (LDAP) server.
Required action (CISA)
Apply updates per vendor instructions.
Ransomware use: CISA marks this vulnerability as known to be used in ransomware campaigns. CISA does not say which group used it.
Links in CISA's notes
Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json
NVD analysis
- Status
- Analyzed
- Published
- 2020-08-14T16:15:16.070
- Last modified
- 2026-08-15T04:17:41.413
- Weaknesses
- CWE-306
A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.
| Metric | Score | Severity | Vector | Scored by |
|---|---|---|---|---|
| CVSS 3.1 | 6.5 | MEDIUM | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | [email protected] (Primary) |
| CVSS 3.1 | 6.5 | MEDIUM | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
| CVSS 2.0 | 3.3 | LOW | AV:A/AC:L/Au:N/C:P/I:N/A:N | [email protected] (Primary) |
References
- https://www.fortiguard.com/psirt/FG-IR-19-037 (Mitigation, Vendor Advisory)
- https://www.fortiguard.com/psirt/FG-IR-19-037 (Mitigation, Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-5591 (US Government Resource)
This product uses the NVD API but is not endorsed or certified by the NVD.
Read on 2026-11-02T23:41:51.476Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2019-5591
CVE record
- Assigner
- fortinet
- State
- PUBLISHED
- Published
- 2020-08-14T15:28:25.000Z
- Updated
- 2026-08-15T03:55:26.471Z
- Problem types
- Information disclosure
A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.
References
Read on 2026-11-03T01:02:08.555Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2019/5xxx/CVE-2019-5591.json
Defensive techniques (MITRE D3FEND)
D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.
CWE-306: Missing Authentication for Critical Function
- Model: Asset Vulnerability Enumeration (acts on Software)
- Isolate: Application-based Process Isolation (acts on Subroutine)
- Harden: Trusted Library (acts on Subroutine)
- Harden: Software Update (acts on Software)
- Restore: Restore Software (acts on Software)
- Model: Software Inventory (acts on Software)
- Harden: Variable Initialization (acts on Subroutine)
- Harden: Domain Logic Validation (acts on Subroutine)
- Harden: Credential Scrubbing (acts on Subroutine)
D3FEND ontology version 1.6.0.
Read on 2026-11-02T23:55:55.098Z under licence d3fend-terms-of-use@f98cbc7e from https://d3fend.mitre.org/api/weakness/cwe/CWE-306.json
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Sources and licences
CISA
Source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30, CC0 1.0. Use of this data does not imply endorsement by CISA or DHS.
National Vulnerability Database (NIST)
This product uses the NVD API but is not endorsed or certified by the NVD.
NVD API Terms of Use (NIST publications in the public domain, 17 U.S.C. 105)
CVE Program, The MITRE Corporation
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MITRE D3FEND
MITRE D3FEND™ knowledge graph. © 2025 The MITRE Corporation.
"The MITRE Corporation (MITRE) hereby grants you a non-exclusive, royalty-free license to use D3FEND for research, development, and commercial purposes. Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." Terms: https://d3fend.mitre.org/tou/MITRE D3FEND Terms of Use (site + knowledge graph); source repo MIT
Cite this page
Dragons Eye Ransomware Tracker, "CVE-2019-5591: Fortinet FortiOS Default Configuration Vulnerability",
entity page, dataset version ref-9887a903b86f, updated 2026-11-02T23:39:54.475Z,
https://ransomware-tracker.com/cve/CVE-2019-5591 (accessed 2026-11-03).
Underlying source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30.
Underlying source: National Vulnerability Database (NIST), CVE API 2.0, record last modified 2026-08-15T04:17:41.413.
Underlying source: CVE List (CVE Program, The MITRE Corporation), record updated 2026-08-15T03:55:26.471Z.
Underlying source: MITRE D3FEND, ontology version 1.6.0.
Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.