CVE-2023-51507Network attack vector

Unauthenticated draft quiz submission via missing status check

Published Jun 14, 2024 · Updated Apr 28, 2026

Missing authorization in Quiz and Survey Master 8.1.16 and earlier allows remote attackers to submit responses to draft quizzes. The public quiz-submission path accepts a quiz identifier without rejecting a quiz whose backing custom post remains in draft status. No account or user interaction is required, and successful requests can add response data for content that administrators have not published.

CVSS severity5.3
Medium
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in Quiz and Survey Master 8.1.16 and earlier allows remote attackers to submit responses to draft quizzes. The public quiz-submission path accepts a quiz identifier without rejecting a quiz whose backing custom post remains in draft status. No account or user interaction is required, and successful requests can add response data for content that administrators have not published.

The record

CVE
CVE-2023-51507
Published
Jun 14, 2024
Updated
Apr 28, 2026
Vendor
ExpressTech Systems
Product
Quiz and Survey Master
Classifications
CWE-862, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 14, 2024CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 2026Record 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=0 <=8.1.16
  2. Affected versionversion=n/a <=8.1.16 changes=[{"at":"8.1.17","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ExpressTech Systems · Quiz and Survey Masterversion=0 <=8.1.16; version=n/a <=8.1.16 changes=[{"at":"8.1.17","status":"unaffected"}]

Published CVSS scores

5.3PatchstackCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization
T1190Exploit Public-Facing Application

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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