Improper certificate validation in Fortinet FortiOS
Priority LOW 33CWE-295Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Spoofing
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-295.
Summary
An improper following of a certificate's chain of trust vulnerability in FortiGate versions 6.4.0 to 6.4.4 may allow an LDAP user to connect to SSLVPN with any certificate that is signed by a trusted Certificate Authority.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0048 41st 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
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-24012
- 2026-10-03 Alias added: GHSA-2fg7-gvqp-mhcc
References
More Fortinet Fortios vulnerabilities
- 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
Sources
- CVE-2021-24012 · CVE Program
- CVE-2021-24012 · NVD
- FIRST EPSS
- GHSA-2fg7-gvqp-mhcc · GitHub Advisory Database · CC BY 4.0
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