CVE-2021-24633Public exploitNetwork attack vector

Subscriber-level post-content modification via unchecked AJAX write

Published Sep 27, 2021 · Updated Aug 3, 2024

Missing authorization in WPDeveloper Countdown Block before 1.1.2 allows remote authenticated users to alter displayed post content. The eb_write_block_css AJAX action accepts a post ID and attacker-controlled CSS data without checking whether the caller may edit that post, then persists styles that change its rendered content. Subscriber-level access is sufficient, and the demonstrated consequence is persistent alteration of the selected post's visible presentation.

CVSS severity4.3
Medium
EPSS probability0.67%
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 WPDeveloper Countdown Block before 1.1.2 allows remote authenticated users to alter displayed post content. The eb_write_block_css AJAX action accepts a post ID and attacker-controlled CSS data without checking whether the caller may edit that post, then persists styles that change its rendered content. Subscriber-level access is sufficient, and the demonstrated consequence is persistent alteration of the selected post's visible presentation.

The record

CVE
CVE-2021-24633
Published
Sep 27, 2021
Updated
Aug 3, 2024
Vendor
WPDeveloper
Product
Countdown Block
Classifications
CWE-862, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 27, 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=1.1.2 <1.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

WPDeveloper · Countdown Blockversion=1.1.2 <1.1.2

Published CVSS scores

4.0NVDAV:N/AC:L/Au:S/C:N/I:P/A:N
4.3NVDCVSS:3.1/AV:N/AC:L/PR:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
T1565.001Stored Data Manipulation

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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