The WPForms – Easy Form Builder for WordPress – Contact Forms, Payment Forms, Surveys, & More plugin for WordPress is vulnerable to Improper Neutralization of CRLF Sequences (CRLF Injection) in all versions up to, and including, 1.10.2 This is due to get_reply_to_address() processing the Reply-To display name through smart-tag expansion with context notification instead of notification-reply-to, which bypasses email-address validation while wpforms_sanitize_textarea_field() intentionally preserves CR/LF characters that are never stripped before the display name is concatenated into the raw Reply-To: mail header string. This makes it possible for unauthenticated attackers to inject arbitrary additional email headers — such as Bcc: — into outgoing notification emails, silently blind-copying all notification email copies to an attacker-controlled address. Exploitation requires that a form notification is configured to use a Paragraph Text (textarea) field as the Reply-To display name via a Smart Tag.
Weakness
The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.
Potential Mitigations
Related Attack Patterns
References
- https://plugins.trac.wordpress.org/browser/wpforms-lite/tags/1.10.0.2/includes/fields/class-textarea.php#L326
- https://plugins.trac.wordpress.org/browser/wpforms-lite/tags/1.10.0.2/src/Emails/Mailer.php#L368
- https://plugins.trac.wordpress.org/browser/wpforms-lite/tags/1.10.0.2/src/Emails/Notifications.php#L1098
- https://plugins.trac.wordpress.org/browser/wpforms-lite/tags/1.10.0.2/src/Emails/Notifications.php#L1138
- https://plugins.trac.wordpress.org/browser/wpforms-lite/tags/1.10.1.1/includes/fields/class-textarea.php#L326
- https://plugins.trac.wordpress.org/browser/wpforms-lite/tags/1.10.1.1/src/Emails/Mailer.php#L368
- https://plugins.trac.wordpress.org/browser/wpforms-lite/tags/1.10.1.1/src/Emails/Notifications.php#L1098
- https://plugins.trac.wordpress.org/browser/wpforms-lite/tags/1.10.1.1/src/Emails/Notifications.php#L1138
- https://plugins.trac.wordpress.org/changeset/3586095/wpforms-lite/trunk/src/Emails/Mailer.php
- https://plugins.trac.wordpress.org/changeset?old_path=%2Fwpforms-lite/tags/1.10.2\u0026new_path=%2Fwpforms-lite/tags/1.10.2.1
- https://www.wordfence.com/threat-intel/vulnerabilities/id/d5a51c22-c4ca-4897-ad7e-c5df00b07fe0?source=cve