Simple Download Monitor < 3.9.5 - Contributor+ Stored Cross-Site Scripting via File Thumbnail

Description

The plugin does not escape the "File Thumbnail" post meta before outputting it in some pages, which could allow users with a role as low as Contributor to perform Stored Cross-Site Scripting attacks. Given the that XSS is triggered even when the Download is in a review state, contributor could make JavaScript code execute in a context of a reviewer such as admin and make them create a rogue admin account, or install a malicious plugin