This indicates an attack attempt against a Cross-Site Scripting (XSS) vulnerability in Synology DiskStation Manager (DSM) Audio 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.
Audio Station version 5.4-2855
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.