PostX < 4.0.2 - Contributor+ Stored XSS

Description The plugin does not validate and escape some of its block options before outputting them back in a page/post where the block is embed, which could allow users with the contributor role and above to perform Stored Cross-Site Scripting attacks

PoC

1. Create a new Post and add “Ultimate post Heading” block. Change “headingURL” field to 123" onmouseover=alert(1)// 2. Browse the post and hover over the heading.