CVE-2021-20876Network attack vector

Sensitive file disclosure via undisclosed path traversal

Published Dec 24, 2021 · Updated Aug 3, 2024

Path traversal in GroupSession Free edition, byCloud, and ZION 5.1.1 and earlier allows remote authenticated users to read sensitive server files. Japan Total System has not disclosed the affected function or request parameter because it considers the target feature and reproduction steps usable for attacks. Administrative access is required, and exposure is limited to information stored above the directory published by the site.

CVSS severity4.9
Medium
EPSS probability1.03%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in GroupSession Free edition, byCloud, and ZION 5.1.1 and earlier allows remote authenticated users to read sensitive server files. Japan Total System has not disclosed the affected function or request parameter because it considers the target feature and reproduction steps usable for attacks. Administrative access is required, and exposure is limited to information stored above the directory published by the site.

The record

CVE
CVE-2021-20876
Published
Dec 24, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-22, T1005
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Dec 24, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.0NIST NVDAV:N/AC:L/Au:S/C:P/I:N/A:N
4.0JPCERT/CC and IPAAV:N/AC:L/Au:S/C:P/I:N/A:N
6.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N
4.9JPCERT/CC and IPACVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1005Data from Local System

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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