CVE-2021-39503Public exploitNetwork attack vector

Authenticated code execution via unsafe configuration generation

Published Sep 7, 2021 · Updated Aug 4, 2024

Code injection in PHPMyWind 5.6 allows remote authenticated users to execute arbitrary PHP code through the site administration interface. The admin/site_save.php handler passes a crafted site_key to WriteConfig(), which closes PHP syntax and writes attacker-controlled code into include/config.cache.php. Administrator access is required; loading an admin PHP page then executes the injected code with the web server's privileges.

CVSS severity7.2
High
EPSS probability2.82%
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 PHPMyWind 5.6 allows remote authenticated users to execute arbitrary PHP code through the site administration interface. The admin/site_save.php handler passes a crafted site_key to WriteConfig(), which closes PHP syntax and writes attacker-controlled code into include/config.cache.php. Administrator access is required; loading an admin PHP page then executes the injected code with the web server's privileges.

The record

CVE
CVE-2021-39503
Published
Sep 7, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-94, T1190, T1505.003
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Sep 7, 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 privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
7.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
T1190Exploit Public-Facing Application
T1505.003Web 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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