CVE-2021-34076Public exploitNetwork attack vector

Authenticated code execution via unfiltered ZIP extraction

Published May 11, 2023 · Updated Jan 27, 2025

Unrestricted file upload in PHPOK 5.7.140 allows remote authenticated users to execute arbitrary code via a crafted ZIP archive. The application-import workflow passes archive contents to ZipArchive::extractTo without validating file types, allowing PHP files to be written under _app. Administrative backend access and development mode are required, and executing the extracted PHP file compromises the web server account.

CVSS severity8.8
High
EPSS probability0.86%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unrestricted file upload in PHPOK 5.7.140 allows remote authenticated users to execute arbitrary code via a crafted ZIP archive. The application-import workflow passes archive contents to ZipArchive::extractTo without validating file types, allowing PHP files to be written under _app. Administrative backend access and development mode are required, and executing the extracted PHP file compromises the web server account.

The record

CVE
CVE-2021-34076
Published
May 11, 2023
Updated
Jan 27, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-434, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 11, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 27, 2025Record 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

8.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.8NIST NVDCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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
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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