CVE-2026-4329
Description
The Blackhole for Bad Bots plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the User-Agent HTTP header in all versions up to and including 3.8. This is due to insufficient input sanitization and output escaping. The plugin uses sanitize_text_field() when capturing bot data (which strips HTML tags but does not escape HTML entities like double quotes), then stores the data via update_option(). When an administrator views the Bad Bots log page, the stored data is output directly into HTML input value attributes (lines 75-83) without esc_attr() and into HTML span content without esc_html(). This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute when an administrator views the Blackhole Bad Bots admin page.
References
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/badbots-register.php#L75
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/badbots-register.php#L79
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/badbots-register.php#L85
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/blackhole-core.php#L180
- https://plugins.trac.wordpress.org/browser/blackhole-bad-bots/tags/3.8/inc/blackhole-helpers.php#L22