AIX's writesrv daemon — accepts remote write messages to users' terminals.
On IBM AIX, writesrv listens on the port named in /etc/services (1334) and handles incoming requests from the write command, spawning a server process per request so a user on one host can write messages to a logged-in user's terminal on another. Both hosts must be running the daemon for remote write to work. It is an old inetd-era convenience service that AIX hardening guides tell you to disable, and it is the only well-documented user of this port.
Do not expose
IBM's own guidance is to disable writesrv on any system connected to a public network; it accepts unauthenticated terminal messages and offers nothing worth the risk.
$ lssrc -s writesrvSeen this on your network? Beige Box scans your Wi-Fi and shows every open port on every device — and its Ports tool links straight back here.
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