CVE-2020-9440Network attack vector

Script execution via unneutralized IFRAME content

Published Mar 10, 2020 · Updated Aug 4, 2024

Cross-site scripting in the WSC plugin through 5.5.7.5 for CKEditor 4 allows remote attackers to execute script inside the editor. The WSC integration renders a crafted HTML element inside an IFRAME without neutralizing its executable content. Exploitation requires a user to paste attacker-supplied HTML in source or WYSIWYG mode and then render it; the reported impact is script execution in the IFRAME.

CVSS severity6.1
Medium
EPSS probability1.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in the WSC plugin through 5.5.7.5 for CKEditor 4 allows remote attackers to execute script inside the editor. The WSC integration renders a crafted HTML element inside an IFRAME without neutralizing its executable content. Exploitation requires a user to paste attacker-supplied HTML in source or WYSIWYG mode and then render it; the reported impact is script execution in the IFRAME.

The record

CVE
CVE-2020-9440
Published
Mar 10, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 10, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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

4.3NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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-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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