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CVE-2019-5591 (GCVE-0-2019-5591)

Vulnerability from cvelistv5 – Published: 2020-08-14 15:28 – Updated: 2026-08-15 03:55
VLAI CISA Previdian
Summary
A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.
Severity
6.5 (Medium)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
SSVC
Exploitation: active Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2021-04-22 00:00 UTC
CWE
  • Information disclosure
  • CWE-306 - Missing Authentication for Critical Function
Assigner
References
Impacted products
Vendor Product Version CPE status
Fortinet Fortinet FortiOS Affected: FortiOS 6.2.0 and below.
guessed Create a notification for this product.
CISA
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: a5a9db0f-c41d-4065-9c8d-6e1affdc0c0b

Vulnerability ID: CVE-2019-5591

Status: Confirmed

Status Updated: 2021-11-03 00:00 UTC

Exploited: Yes

Timestamps
First Seen: 2021-11-03
Asserted: 2021-11-03
Scope
Notes: KEV entry: Fortinet FortiOS Default Configuration Vulnerability | Affected: Fortinet / FortiOS | Description: 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: Apply updates per vendor instructions. | Due date: 2022-05-03 | Known ransomware campaign use (KEV): Unknown | Notes (KEV): https://nvd.nist.gov/vuln/detail/CVE-2019-5591
Evidence

Type: Vendor Report

Signal: Successful Exploitation

Confidence: 80%

Source: cisa-kev

Details
Cwes CWE-306
Feed CISA Known Exploited Vulnerabilities Catalog
Product FortiOS
Due Date 2022-05-03
Date Added 2021-11-03
Vendorproject Fortinet
Vulnerabilityname Fortinet FortiOS Default Configuration Vulnerability
Knownransomwarecampaignuse Unknown
References
Created: 2026-02-02 13:26 UTC | Updated: 2026-02-06 07:53 UTC
Previdian
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 33a61943-a60f-415a-909e-4f83be81f2ee

Vulnerability ID: CVE-2019-5591

Status: Confirmed

Status Updated: 2021-11-03 00:00 UTC

Exploited: Yes

Timestamps
First Seen: 2021-11-03
Asserted: 2021-11-03
Scope
Notes: KEVIntel entry: A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by... | Affected: Fortinet / Fortinet FortiOS | CVSS: 6.5 (MEDIUM) | Used in malware: unknown | Not yet in CISA KEV: False
Evidence

Type: Public Report

Signal: Successful Exploitation

Confidence: 70%

Source: kevintel

Details
Feed KEVIntel (kevintel.com)
Title A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by...
Vendor Fortinet
Product Fortinet FortiOS
Added Date 2021-11-03T00:00:00.000Z
Cvss Score 6.5
Epss Score None
Cvss Severity MEDIUM
Epss Percentile None
Used In Malware unknown
Ahead Of Cisa Kev None
Not Yet In Cisa Kev False
References
Created: 2026-06-23 11:13 UTC | Updated: 2026-06-23 11:13 UTC
Show details on NVD website
To clipboard 

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Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.