An insecure unserialize vulnerability was discovered in ThinkAdmin versions 4.x through 6.x in app/admin/controller/api/Update.php and app/wechat/controller/api/Push.php, which may lead to arbitrary remote code execution.
https://github.com/zoujingli/ThinkAdmin/issues/238
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-23653