CVE-2021-24743Public exploitNetwork attack vector

Stored XSS via unescaped shortcode alignment attribute

Published Oct 18, 2021 · Updated Aug 3, 2024

Stored XSS in SecondLineThemes Podcast Subscribe Buttons before 1.4.2 allows remote authenticated users to execute script via a shortcode. The shortcode renderer inserts the alignment attribute into generated page markup without neutralizing quote-breaking event-handler content. Any role that can add or edit posts can store the payload, which executes in a visitor's browser when the affected page is viewed.

CVSS severity5.4
Medium
EPSS probability0.62%
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 SecondLineThemes Podcast Subscribe Buttons before 1.4.2 allows remote authenticated users to execute script via a shortcode. The shortcode renderer inserts the alignment attribute into generated page markup without neutralizing quote-breaking event-handler content. Any role that can add or edit posts can store the payload, which executes in a visitor's browser when the affected page is viewed.

The record

CVE
CVE-2021-24743
Published
Oct 18, 2021
Updated
Aug 3, 2024
Vendor
SecondLineThemes
Product
Podcast Subscribe Buttons
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 18, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.4.2 <1.4.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

SecondLineThemes · Podcast Subscribe Buttonsversion=1.4.2 <1.4.2

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5NIST NVDAV:N/AC:M/Au:S/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.

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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

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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