CVE-2023-36639Network attack vector

Authenticated code execution via HTTPSd format string

Published Dec 13, 2023 · Updated Aug 2, 2024

Format string injection in Fortinet FortiOS, FortiProxy, and FortiPAM allows remote authenticated users to execute code via crafted API requests. The HTTPSd daemon treats attacker-controlled API data as a format string rather than inert input. A privileged administrative account and network access to the management API are required, and successful exploitation compromises the appliance.

CVSS severity7.2
High
EPSS probability1.06%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Format string injection in Fortinet FortiOS, FortiProxy, and FortiPAM allows remote authenticated users to execute code via crafted API requests. The HTTPSd daemon treats attacker-controlled API data as a format string rather than inert input. A privileged administrative account and network access to the management API are required, and successful exploitation compromises the appliance.

The record

CVE
CVE-2023-36639
Published
Dec 13, 2023
Updated
Aug 2, 2024
Vendor
Fortinet
Product
FortiOS
Classifications
CWE-134, T1190
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Dec 13, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record 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=6.0.0 <=6.0.17
  2. Affected versionversion=6.2.0 <=6.2.15
  3. Affected versionversion=6.4.0 <=6.4.12
  4. Affected versionversion=7.0.0 <=7.0.11
  5. Affected versionversion=7.2.0 <=7.2.4
  6. Affected versionversion=7.4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Fortinet · FortiOSversion=6.0.0 <=6.0.17; version=6.2.0 <=6.2.15; version=6.4.0 <=6.4.12; version=7.0.0 <=7.0.11; version=7.2.0 <=7.2.4; version=7.4.0
Fortinet · FortiPAMversion=1.0.0 <=1.0.3; version=1.1.0
Fortinet · FortiProxyversion=7.0.0 <=7.0.10; version=7.2.0 <=7.2.4

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2Fortinet, Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-134Use of Externally-Controlled Format String
T1190Exploit Public-Facing Application

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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