SSDP is the basis of the discovery protocol of Universal Plug and Play (UPnP) and is intended for use in residential or small office environments.
Many devices, including some residential routers, have a vulnerability in the UPnP software that allows an attacker to get replies from port number 1900 to a destination address of their choice.
With a botnet of thousands of devices, the attackers can generate sufficient packet rates and occupy bandwidth to saturate links, causing the denial of services.
[10] Firefox for Android prior to version 79 did not properly validate the schema of the URL received in SSDP and were vulnerable to remote code execution.
An attacker on the same network could create a malicious server pretending to be a device supporting casting, but instead of a configuration file it would return an intent:// URL.