Internet-Security.com TCP port 9209 details

IANA assigns TCP port 9209 to WAP-WTA-S (Wireless Telephony Application – Secure), part of the legacy WAP/OMA stack used by early mobile carriers. Real deployments included carrier WAP gateways from vendors like Openwave/Phone.com and Nokia that served secure WTA content on this port.
Elasticsearch and OpenSearch may also listen on 9209 for their HTTP REST API: by default they use 9200 and, if occupied, auto-increment within the 9200–9299 range, so a host running multiple nodes often ends up with one on 9209.
Attackers frequently scan the entire 9200–9299 range for exposed Elasticsearch/OpenSearch endpoints, so 9209 is sometimes targeted in those sweeps (data exposure and ransomware have resulted from unsecured instances).

TCP 9209