Hello Adrian,
On Fri, Jun 13, 2025 at 06:27:06AM +0000, Adrian Lutu wrote:
>
> I have found a possible bug in the telnet utility version
> telnet-0.17-85.el9.x86_64. It generates a core dump. I am unsure of
> how to reproduce the issue.
Thanks for the report. The telnet version "telnet-0.17-85.el9.x86_64"
pertains to the (defunct) NetKit project, not GNU Inetutils. This mailing
list is for GNU Inetutils.
On GNU/Linux, the command "telnet 0" results in the telnet client
attempting to connect to TCP port 23 of the system it is running on.
If something was listening on that port on your machine when you
experienced this issue, whatever that was could have sent some data that
crashed telnet.
With nothing listening on TCP port 23 of localhost, with both NetKit
telnet on Ubuntu 22.04 LTS and with current GNU Inetutils telnet, I just
get "Connection refused":
$ # NetKit telnet client
$ readlink -f `which telnet`
/usr/bin/telnet.netkit
$ telnet 0
Trying 0.0.0.0...
telnet: Unable to connect to remote host: Connection refused
$ # GNU Inetutils telnet client
$ ./telnet/telnet --version
telnet (GNU inetutils) 2.6.4-9ab1
Copyright (C) 2025 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Written by many authors.
$ ./telnet/telnet 0
Trying 0.0.0.0...
telnet: Unable to connect to remote host: Connection refused
If you can find out how to reproduce the issue with NetKit telnet, you
could test it with GNU Inetutils telnet. Should the issue also affect
GNU Inetutils telnet, then it would be great if you could report it here
together with a way to reproduce it.
Best regards,
Erik
