CVE-2020-5553Network attack vector

Unauthenticated PHP code execution via arbitrary file upload

Published Mar 25, 2020 · Updated Aug 4, 2024

Code injection in keitai-site.net mailform 1.04 allows remote attackers to execute arbitrary PHP code through a file upload. The mail-form handler accepts arbitrary PHP file uploads and permits the server to execute the uploaded content. No authentication or user interaction is required; successful exploitation grants code execution with the web server process's privileges.

CVSS severity7.3
High
EPSS probability2.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in keitai-site.net mailform 1.04 allows remote attackers to execute arbitrary PHP code through a file upload. The mail-form handler accepts arbitrary PHP file uploads and permits the server to execute the uploaded content. No authentication or user interaction is required; successful exploitation grants code execution with the web server process's privileges.

The record

CVE
CVE-2020-5553
Published
Mar 25, 2020
Updated
Aug 4, 2024
Vendor
keitai-site.net
Product
mailform
Classifications
CWE-94, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 25, 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?

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

  1. Affected versionversion=version 1.04

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

keitai-site.net · mailformversion=version 1.04

Published CVSS scores

7.3JPCERT/CCCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
7.5JPCERT/CCAV: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.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
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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