CVE-2020-13384Public exploitNetwork attack vector

Authenticated arbitrary code execution via unrestricted PHP upload

Published May 22, 2020 · Updated Aug 4, 2024

Remote authenticated users can upload and execute arbitrary PHP code in Monstra CMS 3.0.4 through the administrative files manager. The upload filter blocks filenames ending in .php but accepts alternate PHP extensions such as .php7, allowing a server-executable shell to be placed in the public uploads directory and invoked over HTTP. Exploitation requires valid administrative-interface credentials; successful attacks provide code execution with the privileges of the web server and can compromise hosted content and data.

CVSS severity8.8
High
EPSS probability2.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Remote authenticated users can upload and execute arbitrary PHP code in Monstra CMS 3.0.4 through the administrative files manager. The upload filter blocks filenames ending in .php but accepts alternate PHP extensions such as .php7, allowing a server-executable shell to be placed in the public uploads directory and invoked over HTTP. Exploitation requires valid administrative-interface credentials; successful attacks provide code execution with the privileges of the web server and can compromise hosted content and data.

The record

CVE
CVE-2020-13384
Published
May 22, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-434, T1505.003, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 22, 2020CVE 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NISTAV:N/AC:L/Au:S/C:P/I:P/A:P
8.8NISTCVSS: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 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
T1505.003Web Shell
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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