CVE-2021-20655Network attack vector

Authenticated OS command execution via undisclosed vector

Published Feb 17, 2021 · Updated Aug 3, 2024

OS command injection in FileZen 3.0.0 through 4.2.7 and 5.0.0 through 5.0.2 allows remote authenticated users to execute OS commands. Soliton Systems K.K. has not published the affected parameter, handler, or shell invocation that fails to neutralize command input. Access to a system administrator account is required; successful exploitation permits arbitrary command execution on the appliance.

CVSS severity9.1
Critical
EPSS probability3.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in FileZen 3.0.0 through 4.2.7 and 5.0.0 through 5.0.2 allows remote authenticated users to execute OS commands. Soliton Systems K.K. has not published the affected parameter, handler, or shell invocation that fails to neutralize command input. Access to a system administrator account is required; successful exploitation permits arbitrary command execution on the appliance.

The record

CVE
CVE-2021-20655
Published
Feb 17, 2021
Updated
Aug 3, 2024
Vendor
Soliton Systems K.K.
Product
FileZen
Classifications
CWE-78, T1059
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Feb 17, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=V3.0.0 to V4.2.7 and V5.0.0 to V5.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Soliton Systems K.K. · FileZenversion=V3.0.0 to V4.2.7 and V5.0.0 to V5.0.2

Published CVSS scores

9.1JPCERT/CCCVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
9.0JPCERT/CCAV:N/AC:L/Au:S/C:C/I:C/A:C

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

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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