This indicates an attack attempt against multiple Cross-Site Scripting (XSS) vulnerabilities in Synology DiskStation Manager (DSM) Video Station.
The vulnerability is due to an error in the application when handling malformed inputs. An attacker can exploit this to execute arbitrary script code within context of the target users browser.
Video Station version 1.5-0770
Other versions may be affected too
System Compromise: Remote attackers can execute arbitrary script code within the context of the target users browser
Apply the most recent upgrade or patch from the vendor.