CVE-2020-37023Public exploitNetwork attack vectorHinoki check available

Authenticated command execution via upload filename rewrite

Published Jan 30, 2026 · Updated Jan 30, 2026

Unrestricted file upload in Koken CMS 0.22.24 allows remote authenticated users to execute commands by uploading a PHP file. The Import Content flow accepts a multipart filename changed from an allowed double-extension image to .php without revalidating the dangerous final extension, then stores it at a web-accessible path. An authenticated Admin Panel session is required; requesting the stored script runs attacker-supplied PHP commands in the web server context.

CVSS severity8.7
High
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Unrestricted file upload in Koken CMS 0.22.24 allows remote authenticated users to execute commands by uploading a PHP file. The Import Content flow accepts a multipart filename changed from an allowed double-extension image to .php without revalidating the dangerous final extension, then stores it at a web-accessible path. An authenticated Admin Panel session is required; requesting the stored script runs attacker-supplied PHP commands in the web server context.

The record

CVE
CVE-2020-37023
Published
Jan 30, 2026
Updated
Jan 30, 2026
Vendor
Koken
Product
Koken CMS
Classifications
CWE-434, T1505.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 30, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 30, 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=0.22.24

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Koken · Koken CMSversion=0.22.24

Published CVSS scores

8.7GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA: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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1505.003Server Software Component: Web Shell

Public exploit references

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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