CVE-2021-31707Network attack vector

Unauthenticated code execution via dangerous file upload

Published Apr 4, 2023 · Updated Feb 18, 2025

Unrestricted file upload in KiteCMS allows remote attackers to execute arbitrary code by submitting a dangerous file type. The CNA identifies an unsafe upload-file-type permission check but does not disclose the affected endpoint, function, or exact validation failure. Network access without authentication or user interaction is sufficient, and successful exploitation executes attacker-controlled code on the server.

CVSS severity9.8
Critical
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 KiteCMS allows remote attackers to execute arbitrary code by submitting a dangerous file type. The CNA identifies an unsafe upload-file-type permission check but does not disclose the affected endpoint, function, or exact validation failure. Network access without authentication or user interaction is sufficient, and successful exploitation executes attacker-controlled code on the server.

The record

CVE
CVE-2021-31707
Published
Apr 4, 2023
Updated
Feb 18, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-434, CAPEC-1, T1190
Attack vector
network
Privileges
unauthenticated

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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
CAPEC-1Accessing Functionality Not Properly Constrained by ACLs
T1190Exploit Public-Facing Application

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.

Technologies

Your stack

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Your stack

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