CVE-2023-47537Network attack vector

FortiLink interception via improper certificate validation

Published Feb 15, 2024 · Updated Jan 14, 2026

Improper certificate validation in Fortinet FortiOS allows remote attackers to intercept traffic on the FortiLink channel. The FortiLink endpoint fails to validate its peer certificate when establishing the management channel between FortiOS and FortiSwitch. An unauthenticated attacker positioned on that network path can read or alter channel data, while the published assessment reports no availability impact.

CVSS severity4.8
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper certificate validation in Fortinet FortiOS allows remote attackers to intercept traffic on the FortiLink channel. The FortiLink endpoint fails to validate its peer certificate when establishing the management channel between FortiOS and FortiSwitch. An unauthenticated attacker positioned on that network path can read or alter channel data, while the published assessment reports no availability impact.

The record

CVE
CVE-2023-47537
Published
Feb 15, 2024
Updated
Jan 14, 2026
Vendor
Fortinet
Product
FortiOS
Classifications
CWE-295, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 15, 2024CVE publishedPublication date reported by the CVE source.
  2. Jan 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.4.0
  2. Affected versionversion=6.4.0 <=6.4.16
  3. Affected versionversion=7.0.0
  4. Affected versionversion=7.0.0 <=7.0.15
  5. Affected versionversion=7.2.0
  6. Affected versionversion=7.2.0 <=7.2.6
  7. Affected versionversion=7.4.0
  8. Affected versionversion=7.4.0 <=7.4.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Fortinet · FortiOSversion=6.4.0; version=6.4.0 <=6.4.16; version=7.0.0; version=7.0.0 <=7.0.15; version=7.2.0; version=7.2.0 <=7.2.6; version=7.4.0; version=7.4.0 <=7.4.1

Published CVSS scores

4.8NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
4.8Fortinet, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-295Improper Certificate Validation
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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