4 ms·
On my Ubuntu 22.04 machine, cupsd itself is only listening on localhost, but cups-browsed (which is what has the vulnerability here) is listening on 0.0.0.0
by mikepavone 2y ago
On my Ubuntu 22.04 machine, cupsd itself is only listening on localhost, but cups-browsed (which is what has the vulnerability here) is listening on 0.0.0.0
- raverbashing 2y agoWhy does it even listens in UDP at this day and age?!
- mikepavone 2y agoI believe it's implementing DNS-SD for network printer auto-discovery. I'm not terribly familiar with DNS-SD, but given that normal DNS is UDP based it would be unsurprising for DNS-SD to also use UDP.
- ahoka 2y agoDNS is actually UDP/TCP. It’s probably required for receiving unicast messages, if it’s using DNS-SD
- ahoka 2y agoTo receive multicast messages, probably.
- yrro 2y agoThe purpose of cups-browsed is to listen on a UDP port which allows it to receive broadcasts from legacy cups servers on the local network, whereupon it will talk to cups and configure a local print queue for the printers on the discovered server. A modern setup doesn't need it and doesn't use it.