CVE-2020-23691Public exploitNetwork attack vector

Unauthenticated command execution via request-filter override

Published May 14, 2021 · Updated Aug 4, 2024

Remote code execution in YFCMF 2.3.1 allows remote attackers to execute operating-system commands through the index.php endpoint. The front controller accepts crafted POST parameters that replace the request method and filter with attacker-controlled values, causing the filter callback to invoke the PHP system function on the supplied command. No authentication or user interaction is required, and successful requests run commands with the web application's operating-system privileges.

CVSS severity9.8
Critical
EPSS probability3.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Remote code execution in YFCMF 2.3.1 allows remote attackers to execute operating-system commands through the index.php endpoint. The front controller accepts crafted POST parameters that replace the request method and filter with attacker-controlled values, causing the filter callback to invoke the PHP system function on the supplied command. No authentication or user interaction is required, and successful requests run commands with the web application's operating-system privileges.

The record

CVE
CVE-2020-23691
Published
May 14, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 14, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/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.

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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 exploitPublished

Weakness, pattern, technique

T1190Exploit Public-Facing Application

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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