Description
The HTTP Headers plugin for WordPress is vulnerable to CRLF Injection in all versions up to, and including, 1.19.2. This is due to insufficient sanitization of custom header name and value fields before writing them to the Apache .htaccess file via `insert_with_markers()`. This makes it possible for authenticated attackers, with Administrator-level access and above, to inject arbitrary newline characters and additional Apache directives into the .htaccess configuration file via the 'Custom Headers' settings, leading to Apache configuration parse errors and potential site-wide denial of service.
Problem types
CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')
Product status
Any version
Timeline
| 2026-04-21: | Disclosed |
Credits
Kai Aizen
References
www.wordfence.com/...-e899-4046-9421-86fc0c36c245?source=cve
plugins.trac.wordpress.org/...s/tags/1.19.2/http-headers.php
plugins.trac.wordpress.org/...headers/trunk/http-headers.php
plugins.trac.wordpress.org/...s/tags/1.19.2/http-headers.php
plugins.trac.wordpress.org/...headers/trunk/http-headers.php