CVE-2021-20689Network attack vector

Browser script execution via undisclosed input vector

Published Apr 7, 2021 · Updated Aug 3, 2024

Cross-site scripting in WonderLink Yomi-Search 4.22 allows remote attackers to execute arbitrary script in visitors’ browsers via unspecified vectors. The public JVN record confirms script execution when a user opens a Yomi-Search page, but it does not identify the affected CGI endpoint, input field, or failed output-neutralization operation. Exploitation requires a user to access a site running the affected program; the verified effect is browser-side script execution, not server code execution or service interruption.

CVSS severity6.1
Medium
EPSS probability0.76%
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 WonderLink Yomi-Search 4.22 allows remote attackers to execute arbitrary script in visitors’ browsers via unspecified vectors. The public JVN record confirms script execution when a user opens a Yomi-Search page, but it does not identify the affected CGI endpoint, input field, or failed output-neutralization operation. Exploitation requires a user to access a site running the affected program; the verified effect is browser-side script execution, not server code execution or service interruption.

The record

CVE
CVE-2021-20689
Published
Apr 7, 2021
Updated
Aug 3, 2024
Vendor
WonderLink
Product
Yomi-Search
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 7, 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=Ver4.22

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

WonderLink · Yomi-Searchversion=Ver4.22

Published CVSS scores

4.3JPCERT/CC and IPAAV:N/AC:M/Au:N/C:N/I:P/A:N
6.1JPCERT/CC and IPACVSS:3.0/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')
T1189Drive-by Compromise

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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