CVE-2021-24418Public exploitNetwork attack vector

Administrator-level stored XSS via unsanitized psb_positioning

Published Jul 12, 2021 · Updated Aug 3, 2024

Stored XSS in Mark Senff Smooth Scroll Page Up/Down Buttons 1.4 and earlier allows remote authenticated users to run JavaScript via a crafted setting. The settings handler stores the psb_positioning value without proper sanitization or validation, and the plugin later emits the value across the blog. Administrator privileges are required to save the payload, and JavaScript executes when a visitor loads any affected site page.

CVSS severity4.8
Medium
EPSS probability0.63%
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 Mark Senff Smooth Scroll Page Up/Down Buttons 1.4 and earlier allows remote authenticated users to run JavaScript via a crafted setting. The settings handler stores the psb_positioning value without proper sanitization or validation, and the plugin later emits the value across the blog. Administrator privileges are required to save the payload, and JavaScript executes when a visitor loads any affected site page.

The record

CVE
CVE-2021-24418
Published
Jul 12, 2021
Updated
Aug 3, 2024
Vendor
Mark Senff
Product
Smooth Scroll Page Up/Down Buttons
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jul 12, 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=1.4 <=1.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Mark Senff · Smooth Scroll Page Up/Down Buttonsversion=1.4 <=1.4

Published CVSS scores

3.5NVDAV:N/AC:M/Au:S/C:N/I:P/A:N
4.8NVDCVSS:3.1/AV:N/AC:L/PR:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Cross-site Scripting (XSS)
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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