CVE-2023-53950Public exploitNetwork attack vector

Remote code execution via null-byte upload bypass

Published Dec 19, 2025 · Updated Dec 19, 2025

Unrestricted file upload in InnovaStudio WYSIWYG Editor 5.4 and earlier allows remote attackers to place executable ASP shells on the server. The ASP asset manager's i_upload_object_FSO.asp allowlist accepts a name such as shell.asp%00asp.txt, then stores it as shell.asp. An exposed upload endpoint, a writable web directory, and ASP execution enable unauthenticated server-side code execution and arbitrary-path uploads.

CVSS severity9.3
Critical
EPSS probability0.65%
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 InnovaStudio WYSIWYG Editor 5.4 and earlier allows remote attackers to place executable ASP shells on the server. The ASP asset manager's i_upload_object_FSO.asp allowlist accepts a name such as shell.asp%00asp.txt, then stores it as shell.asp. An exposed upload endpoint, a writable web directory, and ASP execution enable unauthenticated server-side code execution and arbitrary-path uploads.

The record

CVE
CVE-2023-53950
Published
Dec 19, 2025
Updated
Dec 19, 2025
Vendor
InnovaStudio
Product
WYSIWYG Editor
Classifications
CWE-434, T1190, T1505.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 19, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=5.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

InnovaStudio · WYSIWYG Editorversion=0 <=5.4

Published CVSS scores

9.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.8VulnCheckCVSS: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
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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