CVE-2021-20651Network attack vector

Arbitrary file overwrite via crafted ZIP filenames

Published Feb 12, 2021 · Updated Aug 3, 2024

Directory traversal in ELECOM File Manager all versions allows remote attackers to write files through a crafted ZIP archive. During archive extraction, the app fails to constrain ZIP entry filenames to the intended directory, so traversal paths escape it and create or overwrite files reachable with the app's privileges. Exploitation requires user interaction with the archive, and the bounded consequence is arbitrary file creation or overwrite within app-accessible storage.

CVSS severity4.3
Medium
EPSS probability1.94%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Directory traversal in ELECOM File Manager all versions allows remote attackers to write files through a crafted ZIP archive. During archive extraction, the app fails to constrain ZIP entry filenames to the intended directory, so traversal paths escape it and create or overwrite files reachable with the app's privileges. Exploitation requires user interaction with the archive, and the bounded consequence is arbitrary file creation or overwrite within app-accessible storage.

The record

CVE
CVE-2021-20651
Published
Feb 12, 2021
Updated
Aug 3, 2024
Vendor
ELECOM CO., LTD.
Product
ELECOM File Manager
Classifications
CWE-22, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 12, 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

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Is a vulnerable build present?

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  1. Affected versionversion=all versions

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ELECOM CO., LTD. · ELECOM File Managerversion=all versions

Published CVSS scores

4.3JPCERT/CCCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
4.3JPCERT/CCAV:N/AC:M/Au:N/C:N/I:P/A:N

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-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1204.002Malicious File

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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