CVE-2021-20735Known exploitationNetwork attack vector

Browser script execution via undisclosed management-page operation

Published Jun 22, 2021 · Updated Aug 3, 2024

Cross-site scripting in ETUNA's three delivery-slip plugins for EC-CUBE 3.0 allows remote attackers to run script in an administrator's browser. The public advisories identify only a specific management-page operation as the trigger and do not disclose the input, code path, or output-encoding failure. Exploitation requires interaction by a user accessing the administrative page; JPCERT/CC reported attacks exploiting the flaw in the wild.

CVSS severity6.1
Medium
EPSS probability1.12%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in ETUNA's three delivery-slip plugins for EC-CUBE 3.0 allows remote attackers to run script in an administrator's browser. The public advisories identify only a specific management-page operation as the trigger and do not disclose the input, code path, or output-encoding failure. Exploitation requires interaction by a user accessing the administrative page; JPCERT/CC reported attacks exploiting the flaw in the wild.

The record

CVE
CVE-2021-20735
Published
Jun 22, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 22, 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3JPCERT/CCAV:N/AC:M/Au:N/C:N/I:P/A:N
6.1JPCERT/CCCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NISTAV: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript/JScript

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.

Reported exploitation

Technologies

Your stack

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Your stack

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