What’s Vulnerable › Vulnerabilities

CVE-2024-3565: Content Blocks (Custom Post Widget) <= 3.3.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via content_block Shortcode

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-06-01 · updated 2026-06-17
• Weakness: CWE-79

Description

The Content Blocks (Custom Post Widget) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'content_block' shortcode in all versions up to, and including, 3.3.0 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Affected products

• vanderwijk Content Blocks (Custom Post Widget): before 3.3.1 — fixed in 3.3.1

How to fix

Upgrade to a fixed version: vanderwijk Content Blocks (Custom Post Widget) 3.3.1. Check the vendor advisory for mitigations.

References

• https://plugins.trac.wordpress.org/browser/custom-post-widget/trunk/shortcode.php#L62
• https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3078739%40custom-post-widget&new=3078739%40custom-post-widget&sfp_email=&sfph_mail=#file6
• https://www.wordfence.com/threat-intel/vulnerabilities/id/16d8eab2-953a-46bf-a0f6-296bcea86305?source=cve
• https://plugins.trac.wordpress.org/browser/custom-post-widget/trunk/shortcode.php#L62
• https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3078739%40custom-post-widget&new=3078739%40custom-post-widget&sfp_email=&sfph_mail=#file6
• https://www.wordfence.com/threat-intel/vulnerabilities/id/16d8eab2-953a-46bf-a0f6-296bcea86305?source=cve

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