CVE-2021-3267Public exploitNetwork attack vector

Authenticated code execution via permissive image upload

Published Apr 4, 2023 · Updated Feb 18, 2025

Unrestricted file upload in Kitesky KiteCMS 1.1 allows remote authenticated users to execute arbitrary code through uploadFile. The upload path uses the administrator-configured image-extension allowlist without MIME validation, while checkImg accepts extensions outside its image list. Backend administrative access and adding PHP to the image allowlist are required; a successful upload creates a web-accessible PHP shell.

CVSS severity7.2
High
EPSS probability1.26%
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 Kitesky KiteCMS 1.1 allows remote authenticated users to execute arbitrary code through uploadFile. The upload path uses the administrator-configured image-extension allowlist without MIME validation, while checkImg accepts extensions outside its image list. Backend administrative access and adding PHP to the image allowlist are required; a successful upload creates a web-accessible PHP shell.

The record

CVE
CVE-2021-3267
Published
Apr 4, 2023
Updated
Feb 18, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-434, T1505.003
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Apr 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 18, 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 privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.2NIST National Vulnerability DatabaseCVSS: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.

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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-434Unrestricted Upload of File with Dangerous Type
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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