HTTP Headers

The HTTP Headers plugin for WordPress is vulnerable to External Control of File Name or Path leading to Remote Code Execution in all versions up to and including 1.19.2. This is due to insufficient validation of the file path stored in the 'hh_htpasswd_path' option and lack of sanitization on the 'hh_www_authenticate_user' option value. The plugin allows administrators to set an arbitrary file path for the htpasswd file location and does not validate that the path has a safe file extension (e.g., restricting to .htpasswd). Additionally, the username field used for HTTP Basic Authentication is written directly into the file without sanitization. The apache_auth_credentials() function constructs the file content using the unsanitized username via sprintf('%s:{SHA}%s', $user, ...), and update_auth_credentials() writes this content to the attacker-controlled path via file_put_contents(). This makes it possible for authenticated attackers, with Administrator-level access and above, to write arbitrary content (including PHP code) to arbitrary file paths on the server, effectively achieving Remote Code Execution.

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.

The HTTP Headers plugin for WordPress is vulnerable to Stored Cross-Site Scripting via admin settings in all versions up to, and including, 1.19.2 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.