CVE-2021-4455Public exploitNetwork attack vector

Unauthenticated file upload via client-controlled extension allowlist

Published Apr 19, 2025 · Updated Apr 8, 2026

Arbitrary file upload in CodeFlist Smart Product Review for WooCommerce 1.0.4 and earlier allows remote attackers to write server files. The unauthenticated sprw_file_upload_action AJAX handler accepts attacker-supplied allowedExtensions values, permitting PHP-family extensions. Successful exploitation writes a chosen file into the site's review-upload area; server execution depends on uploaded-file reachability and PHP handling.

CVSS severity9.8
Critical
EPSS probability0.79%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Arbitrary file upload in CodeFlist Smart Product Review for WooCommerce 1.0.4 and earlier allows remote attackers to write server files. The unauthenticated sprw_file_upload_action AJAX handler accepts attacker-supplied allowedExtensions values, permitting PHP-family extensions. Successful exploitation writes a chosen file into the site's review-upload area; server execution depends on uploaded-file reachability and PHP handling.

The record

CVE
CVE-2021-4455
Published
Apr 19, 2025
Updated
Apr 8, 2026
Vendor
CodeFlist
Product
Smart Product Review for WooCommerce
Classifications
CWE-434, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 2026Record 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=0 <=1.0.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

CodeFlist · Smart Product Review for WooCommerceversion=0 <=1.0.4

Published CVSS scores

9.8WordfenceCVSS: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 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 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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