CVE-2019-17656Network attack vector

Authenticated HTTPD crash via malformed PUT request

Published Apr 12, 2021 · Updated Oct 25, 2024

Stack-based buffer overflow in Fortinet FortiOS and FortiProxy allows remote authenticated users to crash HTTPD via a malformed PUT request. The HTTPD PUT-request handler accepts attacker-controlled malformed request data without enforcing the stack buffer's bounds. Valid credentials and network access to HTTPD are required; the documented consequence is a service crash, and Fortinet reports no successful code execution.

CVSS severity6.5
Medium
EPSS probability1.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Fortinet FortiOS and FortiProxy allows remote authenticated users to crash HTTPD via a malformed PUT request. The HTTPD PUT-request handler accepts attacker-controlled malformed request data without enforcing the stack buffer's bounds. Valid credentials and network access to HTTPD are required; the documented consequence is a service crash, and Fortinet reports no successful code execution.

The record

CVE
CVE-2019-17656
Published
Apr 12, 2021
Updated
Oct 25, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Oct 25, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.4Fortinet, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
6.5NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.0NIST National Vulnerability DatabaseAV:N/AC:L/Au:S/C:N/I:N/A:P

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
T1499Endpoint Denial of Service

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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