CVE-2021-24376Public exploitNetwork attack vector

Unauthenticated code execution via nested archive upload

Published Jun 21, 2021 · Updated Aug 3, 2024

Unrestricted file upload in Optimizing Matters Autoptimize before 2.7.8 allows remote attackers to execute PHP through Import Settings. The import handler extracts the ZIP, but its cleanup checks only top-level files and leaves PHP files placed inside extracted subdirectories on disk. No authentication or user interaction is required; requesting the retained PHP file executes code in the web-server context.

CVSS severity9.8
Critical
EPSS probability3.73%
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 Optimizing Matters Autoptimize before 2.7.8 allows remote attackers to execute PHP through Import Settings. The import handler extracts the ZIP, but its cleanup checks only top-level files and leaves PHP files placed inside extracted subdirectories on disk. No authentication or user interaction is required; requesting the retained PHP file executes code in the web-server context.

The record

CVE
CVE-2021-24376
Published
Jun 21, 2021
Updated
Aug 3, 2024
Vendor
Optimizing Matters
Product
Autoptimize
Classifications
CWE-434, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 21, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=2.7.8 <2.7.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Optimizing Matters · Autoptimizeversion=2.7.8 <2.7.8

Published CVSS scores

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/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
Privilegesunauthenticated
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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