CVE-2021-44159Network attack vector

Unauthenticated code execution via unrestricted file upload

Published Dec 20, 2021 · Updated Sep 17, 2024

Unrestricted file upload in 4MOSAn GCB Doctor 20210811(2.0) and earlier allows remote attackers to execute arbitrary code without authentication. The file upload function accepts arbitrary file types, including server-executable web shells, without enforcing authentication or authorization. Network access to the upload function is sufficient; uploaded code can perform operations with the service privileges or interrupt the service.

CVSS severity9.8
Critical
EPSS probability3.41%
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 4MOSAn GCB Doctor 20210811(2.0) and earlier allows remote attackers to execute arbitrary code without authentication. The file upload function accepts arbitrary file types, including server-executable web shells, without enforcing authentication or authorization. Network access to the upload function is sufficient; uploaded code can perform operations with the service privileges or interrupt the service.

The record

CVE
CVE-2021-44159
Published
Dec 20, 2021
Updated
Sep 17, 2024
Vendor
4MOSAn Security Technology Co., Ltd.
Product
4MOSAn GCB Doctor
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=unspecified <=20210811(2.0)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

4MOSAn Security Technology Co., Ltd. · 4MOSAn GCB Doctorversion=unspecified <=20210811(2.0)

Published CVSS scores

9.8TWCERT/CCCVSS: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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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