Description
WordPress Plugin RSVPMaker is prone to a server-side request forgery vulnerability. An attacker may leverage this issue to make the vulnerable server perform port scanning of hosts in internal or external networks; other attacks are also possible. WordPress Plugin RSVPMaker version 8.7.2 is vulnerable; prior versions may also be affected.
Remediation
Update to plugin version 8.7.4 or latest
References
https://codevigilant.com/disclosure/2021/wp-plugin-rsvpmaker/
https://plugins.trac.wordpress.org/changeset/2536674/rsvpmaker
https://plugins.svn.wordpress.org/rsvpmaker/trunk/README.txt