CVE-2021-43934Network attack vector

Arbitrary file write via unvalidated restore upload

Published Apr 28, 2022 · Updated Apr 16, 2025

Unrestricted file upload in SmartPTT 1.1 allows remote attackers to write arbitrary files through backup and restore upload requests. The backup and restore system processes upload requests without adequately validating the submitted file, so attacker-chosen files pass the upload boundary. No authentication or user interaction is required, and the public record does not disclose the destination path or whether uploaded files execute.

CVSS severity9.8
Critical
EPSS probability1.16%
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 SmartPTT 1.1 allows remote attackers to write arbitrary files through backup and restore upload requests. The backup and restore system processes upload requests without adequately validating the submitted file, so attacker-chosen files pass the upload boundary. No authentication or user interaction is required, and the public record does not disclose the destination path or whether uploaded files execute.

The record

CVE
CVE-2021-43934
Published
Apr 28, 2022
Updated
Apr 16, 2025
Vendor
Elcomplus, Inc.
Product
SmartPTT
Classifications
CWE-434, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 28, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 16, 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=1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Elcomplus, Inc. · SmartPTTversion=1.1

Published CVSS scores

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8ICS-CERTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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
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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