CVE-2021-24220Known exploitationNetwork attack vector

Unauthenticated arbitrary file upload via Kraken endpoint

Published Apr 12, 2021 · Updated Aug 3, 2024

Arbitrary file upload in Thrive Themes Legacy WordPress themes before 2.0.0 allows remote attackers to execute malicious PHP via crafted REST requests. The thrive_kraken_callback() endpoint fetches attacker-controlled code from a remote URL and writes it to an existing or new site file. Exploitation chains an unauthenticated option update with the upload request, enabling backdoor installation and full site compromise.

CVSS severity10.0
Critical
EPSS probability3.95%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Arbitrary file upload in Thrive Themes Legacy WordPress themes before 2.0.0 allows remote attackers to execute malicious PHP via crafted REST requests. The thrive_kraken_callback() endpoint fetches attacker-controlled code from a remote URL and writes it to an existing or new site file. Exploitation chains an unauthenticated option update with the upload request, enabling backdoor installation and full site compromise.

The record

CVE
CVE-2021-24220
Published
Apr 12, 2021
Updated
Aug 3, 2024
Vendor
Thrive Themes
Product
Luxe
Classifications
CWE-434, T1505.003, T1105
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 23, 2021Exploitation reportedActive exploitation of Thrive Legacy Themes
  2. Apr 12, 2021CVE publishedPublication date reported by the CVE source.
  3. 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=2.0.0 <2.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Thrive Themes · Luxeversion=2.0.0 <2.0.0
Thrive Themes · Squaredversion=2.0.0 <2.0.0
Thrive Themes · Pressiveversion=2.0.0 <2.0.0
Thrive Themes · Storiedversion=2.0.0 <2.0.0
Thrive Themes · FocusBlogversion=2.0.0 <2.0.0
Thrive Themes · Minusversion=2.0.0 <2.0.0
Thrive Themes · Voiceversion=2.0.0 <2.0.0
Thrive Themes · Ignitionversion=2.0.0 <2.0.0
Thrive Themes · Riseversion=2.0.0 <2.0.0
Thrive Themes · Performagversion=2.0.0 <2.0.0

Published CVSS scores

10.0WordfenceCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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 exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1505.003Web Shell
T1105Ingress Tool Transfer

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.

Reported exploitation

Technologies

Your stack

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Your stack

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