CVE-2021-35261Public exploitNetwork attack vector

Unauthenticated RCE via unrestricted UEditor upload

Published Feb 17, 2023 · Updated Mar 18, 2025

Unrestricted file upload in Yupoxion BearAdmin before commit 1017615 allows remote attackers to execute arbitrary code without authentication. EditorController passes UEditor requests to UpFile, which saves uploaded files without checking their extensions. The exposed endpoint accepts a PHP payload without login, placing executable code on the web server and enabling full application compromise.

CVSS severity9.8
Critical
EPSS probability0.81%
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 Yupoxion BearAdmin before commit 1017615 allows remote attackers to execute arbitrary code without authentication. EditorController passes UEditor requests to UpFile, which saves uploaded files without checking their extensions. The exposed endpoint accepts a PHP payload without login, placing executable code on the web server and enabling full application compromise.

The record

CVE
CVE-2021-35261
Published
Feb 17, 2023
Updated
Mar 18, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-434, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 17, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 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

9.8National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8CISA-ADPCVSS: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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