Pz-LinkCard < 2.5.3 - Contributor+ SSRF

Description The plugin does not prevent users from pinging arbitrary hosts via some of its shortcodes, which could allow high privilege users such as contributors to perform SSRF attacks.

PoC

Setup a listener on a localhost/LAN host (such as nc -l 127.0.0.1 9000), then as a contributor, put the following shortcode in a post and save its draft: [blogcard url=“http://127.0.0.1:9000”] Notice that the internal server (localhost:9000) received the request when the draft was saved