Dokan < 5.3.3 - Unauthenticated Email Sender Spoofing via Store Contact Form

Description

The plugin does not use a trusted site-owned sender address when relaying its store contact form, instead placing the unauthenticated submitter's supplied address directly in the message's From header rather than a Reply-To, allowing unauthenticated attackers to make the site email its own vendors with the sender spoofed to an address at the site's own domain (such as its administrator), aligned with the domain's own SPF/DKIM.