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TI-2021-17883 Aliases CVE-2021-41019GHSA-hj73-5q9f-3jj4

Improper certificate validation in Fortinet FortiOS

Priority LOW 30CWE-295Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Spoofing
Confidentiality · integrity · availability
High · None · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-295.

Summary

An improper validation of certificate with host mismatch [CWE-297] vulnerability in FortiOS versions 6.4.6 and below may allow the connection to a malicious LDAP server via options in GUI, leading to disclosure of sensitive information, such as AD credentials.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00569 47th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
FortinetFortinet FortiOSFortiOS 6.4.6, 6.4.5, 6.4.4, 6.4.3, 6.4.2, 6.4.1, 6.4.0, 6.2.9, 6.2.8, 6.2.7, 6.2.6, 6.2.5, 6.2.4, 6.2.3, 6.2.2, 6.2.1—No fix listedCNA
  • Fortinet FortiOS VendorFortinet Affected FortiOS 6.4.6, 6.4.5, 6.4.4, 6.4.3, 6.4.2, 6.4.1, 6.4.0, 6.2.9, 6.2.8, 6.2.7, 6.2.6, 6.2.5, 6.2.4, 6.2.3, 6.2.2, 6.2.1 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*6.4.0 – 6.4.6VulnerableFortinet
  • cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:* Versions 6.4.0 – 6.4.6 Vulnerable ·Fortinet

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-41019
  2. 2026-10-03 Alias added: GHSA-hj73-5q9f-3jj4

References

  • TI-2026-20057 Authentication bypass in Fortinet FortiWeb KEVCVSS 3.1CRITICAL 9.4
  • TI-2025-18911 Heap-based buffer overflow in Fortinet FortiSwitchManager KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-36904 Authentication bypass in Fortinet FortiOS KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-15234 A use of externally-controlled format string in Fortinet FortiOS versions 7.4.0 through… KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-14448 Out-of-bounds write in Fortinet FortiOS KEVCVSS 3.1CRITICAL 9.8
  • TI-2023-12585 Heap-based buffer overflow in Fortinet FortiOS-6K7K KEVCVSS 3.1CRITICAL 9.8
See all 276 →

Sources