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CVE-2019-5591

Fortinet FortiOS Default Configuration

6.5 MEDIUMActively exploited (CISA KEV)Used in ransomwareEPSS 18.4%
  1. Published14 Aug 2020
  2. Added to CISA KEV3 Nov 2021
  3. Remediation due3 May 2022
Actively exploited (CISA KEV)

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.

Added to KEV: 3 Nov 2021Federal remediation due: 3 May 2022Used in ransomware

Description

A Default Configuration vulnerability in FortiOS may allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.

CVSS 3.1 breakdown

Attack vectorAdjacent
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityNone
AvailabilityNone
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

Fortinet FortiOS≤ 6.2.0

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

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Frequently asked

Is CVE-2019-5591 being actively exploited?

Yes. CVE-2019-5591 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 3 Nov 2021. It has been used in ransomware campaigns.

How severe is CVE-2019-5591?

CVE-2019-5591 has a CVSS 3.1 base score of 6.5, rated medium. EPSS estimates a 18.4% probability of exploitation.

Which products are affected by CVE-2019-5591?

Affected products include Fortinet FortiOS.

How do I fix CVE-2019-5591?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2019-5591 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, Secuno flags any affected asset as top-priority automatically. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.