Skip to main content
ExploitedIn CISA KEV

CVE-2019-5591

Exploitation confirmed. First attested on 2021-11-03 by CISA-ADP, CISA KEV, GCVE · kevintel.

  • Published2020-08-14
  • WeaknessCWE-306

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2020-08-1416:15CVE publishedNVD
  2. 2021-11-03Added to the CISA KEV catalogCISA KEV
  3. 2021-11-03Listed as exploited by GCVEGCVE
  4. 2021-11-03Exploitation first reportedCISA KEV
  5. 2024-10-2313:30SSVC exploitation set to activeCISA-ADP

Observed activity

isMalicious corpus · updated 2026-11-03 15:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2019-5591?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2019-5591?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Fortinet FortiOS
BranchAffectedFixed in
6.2≤ 6.2.0no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As fortinet, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • Fortinet FortiOS
    Affected
    • = FortiOS 6.2.0 and below.no fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2021-04-07

Fix

  1. CISA’s required action: Apply updates per vendor instructions.due 2022-05-03

Advisories and patches

Detection

read 2026-11-02 22:42 UTC
Nuclei template
available
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
1 repository, unverifiedayewo/fortios-ldap-mitm-poc-CVE-2019-5591
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

CISA Known Exploited Vulnerability

Date Added
2021-11-03
Patch Due Date
2022-05-03
Ransomware Use
Unknown
Required Action
Apply updates per vendor instructions.

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Published
2020-08-14
Last Modified
2026-08-15
NVD status
Analyzed
GitHub Advisory
GHSA-p9g8-h33v-mg42

Frequently asked questions

What is CVE-2019-5591?

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

Is CVE-2019-5591 actively exploited?

Yes. CVE-2019-5591 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2022-05-03.

What is the CVSS score for CVE-2019-5591?

CVE-2019-5591 has a CVSS v3 base score of 6.5 (MEDIUM severity), with vector string CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

Hear about the next vulnerability in your software

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this productCISA KEV additions, November 2021Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database

Sources for this record