CVE-2021-28006Public exploitNetwork attack vector

Stored script execution via unencoded MCQ option

Published Mar 9, 2021 · Updated Aug 3, 2024

Stored XSS in Web Based Quiz System 1.0 allows remote authenticated users to execute script in quiz takers' browsers. The question-creation flow accepts a script-bearing MCQ option, stores it, and renders it without neutralization when a user attempts the quiz. An administrator account is required to plant the payload, and a quiz taker must open the affected question; the script then runs in the application's origin.

CVSS severity6.1
Medium
EPSS probability0.86%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Web Based Quiz System 1.0 allows remote authenticated users to execute script in quiz takers' browsers. The question-creation flow accepts a script-bearing MCQ option, stores it, and renders it without neutralization when a user attempts the quiz. An administrator account is required to plant the payload, and a quiz taker must open the affected question; the script then runs in the application's origin.

The record

CVE
CVE-2021-28006
Published
Mar 9, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Mar 9, 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 privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NVDAV: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.

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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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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

Public exploit references

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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