A Server-Side Request Forgery (SSRF) vulnerability in Group Office 6.4.196 allows a remote attacker to forge GET requests to arbitrary URLs via the url parameter to group/api/upload.php.
https://fatihhcelik.github.io/posts/Group-Office-CRM-SSRF/
https://fatihhcelik.blogspot.com/2020/12/group-office-crm-ssrf.html