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firefox opens a UDP listening port a.k.a backdoor on all network interfaces

jean-christophe manciot
jean-christophe manciot
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On ubuntu oracular 24.10, when firefox is launched, it tries to open a UDP listening port on all network interfaces which is not acceptable on many levels:

/usr/bin/netstat -tunpevaW|grep firefox udp 0 0 0.0.0.0:48654 0.0.0.0:* 1000 881247 178766/firefox

Is this behavior specific to Ubuntu or is it implemented by design? This must be a no go by design: if it needs a UDP port for some reason, it has to open it on the **loopback interface (127.0.0.1)** only.

On ubuntu oracular 24.10, when firefox is launched, it tries to open a UDP listening port on all network interfaces which is not acceptable on many levels: /usr/bin/netstat -tunpevaW|grep firefox udp 0 0 0.0.0.0:48654 0.0.0.0:* 1000 881247 178766/firefox Is this behavior specific to Ubuntu or is it implemented by design? This must be a no go by design: if it needs a UDP port for some reason, it has to open it on the **loopback interface (127.0.0.1)** only.

Modified by jean-christophe manciot

All Replies (1)

Balázs Meskó
Balázs Meskó
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Hi Jean-Christophe!

I found this post about this: https://unix.stackexchange.com/a/769645 According to this and others I found, these are most likely used by HTTP/3, which is partially UDP-based. So this isn't Ubuntu-specific at all.

Regards, Balázs

Modified by Balázs Meskó

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