This indicates an attack attempt to exploit an Arbitrary Code Execution Vulnerability in LibreOffice.
A remote attacker can exploit this vulnerability by enticing a target user into opening a crafted document. Successful exploitation could result in the execution of arbitrary code in the security context of the target user.
LibreOffice prior to 6.2.5
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.