CVE-2021-4293Network attack vector

Stored XSS via me_link scheme bypass

Published Dec 28, 2022 · Updated Aug 3, 2024

Cross-site scripting in YoungCart5 5.4.5.1 and earlier allows remote attackers to execute script in an administrator's browser via crafted me_link input. The adm/menu_list_update.php handler failed to reject javascript-scheme values before sanitizing and storing the menu link, enabling stored script injection when the link is rendered. Exploitation requires access to the administrative menu update function and a victim administrator to view the affected page; impact is script execution in that browser context.

CVSS severity6.1
Medium
EPSS probability0.51%
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 YoungCart5 5.4.5.1 and earlier allows remote attackers to execute script in an administrator's browser via crafted me_link input. The adm/menu_list_update.php handler failed to reject javascript-scheme values before sanitizing and storing the menu link, enabling stored script injection when the link is rendered. Exploitation requires access to the administrative menu update function and a victim administrator to view the affected page; impact is script execution in that browser context.

The record

CVE
CVE-2021-4293
Published
Dec 28, 2022
Updated
Aug 3, 2024
Vendor
GNUBOARD
Product
YoungCart5
Classifications
CWE-79, T1189
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 28, 2022CVE 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=5.4.5.0
  2. Affected versionversion=5.4.5.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GNUBOARD · YoungCart5version=5.4.5.0; version=5.4.5.1

Published CVSS scores

6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
3.5VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Cross 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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