Adobe Document Service allows an attacker with administrator privileges to send a crafted request from a vulnerable web application. It is usually used to target internal systems behind firewalls that are normally inaccessible to an attacker from the external network, resulting in a Server-Side Request Forgery vulnerability. On successful exploitation, the attacker can read or modify any file and/or make the entire system unavailable.
https://www.securityweek.com/sap-patches-critical-vulnerability-in-netweaver/
https://securityaffairs.com/171839/security/sap-fixed-critical-ssrf-flaw-netweaver.html