CVE-2023-22640Network attack vector

Authenticated code execution via SSLVPNd buffer overwrite

Published May 3, 2023 · Updated Oct 23, 2024

Out-of-bounds write in Fortinet FortiOS and FortiProxy allows remote authenticated users to execute unauthorized code via crafted SSL-VPN requests. The SSLVPNd service writes beyond an allocated buffer while processing a specifically crafted authenticated request; Fortinet has not disclosed the affected function or field. Exposure requires SSL-VPN to be enabled and valid credentials, and successful exploitation compromises the device.

CVSS severity8.8
High
EPSS probability0.89%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in Fortinet FortiOS and FortiProxy allows remote authenticated users to execute unauthorized code via crafted SSL-VPN requests. The SSLVPNd service writes beyond an allocated buffer while processing a specifically crafted authenticated request; Fortinet has not disclosed the affected function or field. Exposure requires SSL-VPN to be enabled and valid credentials, and successful exploitation compromises the device.

The record

CVE
CVE-2023-22640
Published
May 3, 2023
Updated
Oct 23, 2024
Vendor
Fortinet
Product
FortiOS
Classifications
CWE-787, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 3, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 23, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=6.0.0 <=6.0.16
  2. Affected versionversion=6.2.0 <=6.2.13
  3. Affected versionversion=6.4.0 <=6.4.11
  4. Affected versionversion=7.0.0 <=7.0.10
  5. Affected versionversion=7.2.0 <=7.2.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Fortinet · FortiOSversion=6.0.0 <=6.0.16; version=6.2.0 <=6.2.13; version=6.4.0 <=6.4.11; version=7.0.0 <=7.0.10; version=7.2.0 <=7.2.3
Fortinet · FortiProxyversion=1.0.0 <=1.0.7; version=1.1.0 <=1.1.6; version=1.2.0 <=1.2.13; version=2.0.0 <=2.0.12; version=7.0.0 <=7.0.7; version=7.2.0 <=7.2.1

Published CVSS scores

7.5Fortinet, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
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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