Security researchers are continuing to see DDoS attacks that leverage the UPnP features of home routers to alter network packets. Arbor Networks report on seeing similar DDoS-based attacks that leveraged the UPNP protocol. The technique was used to mask SSDP-based DDoSDoS attacks. Older DDoS mitigation systems that rely on deep packet inspection (DPI) are capable of detecting these types of attacks that use randomized source ports, but these are more financially costly for users and take more time to detect.
Source: https://www.bleepingcomputer.com/news/security/those-harder-to-mitigate-upnp-powered-ddos-attacks-are-becoming-a-reality/