Async JavaScript <= 2.19.07.14 - Authenticated (Subscriber+) Stored Cross-Site Scripting

Vulnerability Description

The Async JavaScript plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 2.19.07.14. This is due to missing authorization checks on the aj_steps AJAX aciton along with a lack on sanitization on the settings saved via the function. This makes it possible for authenticated attackers with subscriber level permissions and above to inject malicious web scripts into a page that execute whenever a user accesses that page.

References

• https://www.wordfence.com/threat-intel/vulnerabilities/id/b133888c-7673-4796-917c-486bff1b6b12?source=cve
• https://www.wordfence.com/blog/2020/02/site-takeover-campaign-exploits-multiple-zero-day-vulnerabilities/