CVE-2021-20673Network attack vector

Stored script execution through administrator-page input

Published Mar 10, 2021 · Updated Aug 3, 2024

Stored cross-site scripting in the GROWI 4.2.0 through 4.2.7 Admin Page allows remote authenticated users to execute arbitrary script. The public advisories identify the Admin Page as the storage locus but do not disclose which field accepts the script or how output encoding fails. An attacker needs administrator-level access to store the payload, and execution occurs only when a logged-in user views the affected content in a browser.

CVSS severity4.8
Medium
EPSS probability0.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored cross-site scripting in the GROWI 4.2.0 through 4.2.7 Admin Page allows remote authenticated users to execute arbitrary script. The public advisories identify the Admin Page as the storage locus but do not disclose which field accepts the script or how output encoding fails. An attacker needs administrator-level access to store the payload, and execution occurs only when a logged-in user views the affected content in a browser.

The record

CVE
CVE-2021-20673
Published
Mar 10, 2021
Updated
Aug 3, 2024
Vendor
WESEEK, Inc.
Product
GROWI
Classifications
CWE-79, T1203
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Mar 10, 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?

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

  1. Affected versionversion=versions from v4.2.0 to v4.2.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

WESEEK, Inc. · GROWIversion=versions from v4.2.0 to v4.2.7

Published CVSS scores

3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/A:N
4.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
4.8JPCERT/CC and IPACVSS:3.0/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
3.5JPCERT/CC and IPAAV:N/AC:M/Au:S/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 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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

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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