WPForms <= 1.10.2 - Improper Neutralization of CRLF Sequences to Unauthenticated Email Header Injection via Reply-To Display Name

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.