Telnet IS a backdoor
For starters: Telnet is not a protocol. Telnet is a remote access utility. Telnet's underlying protocol is TCP/IP.
Telnet traffic is unencrypted. Yes, that includes transmission of the password. There is a reason why it has been replaced by ssh for just about two decades. Just like there is a reason why http has been (mostly) replaced by https.
A 14-year-old with Wireshark can sniff Telnet traffic. No need for NSA and/or GCHQ.
No, you don't need Telnet to perform remote diagnostics or maintenance. That's pure bullshit. All of this remote administration and maintenance stuff can be done more securely with ssh and an appropriate key length.
And no, Telnet is not a standard remote maintenance utility. It has not been so for 20+ years. Telnet has been deprecated in all Linux and *BSD distros specifically because it's a backdoor.
Name one Linux distro that still installs Telnet by default. I use RHEL, Fedora, SUSE and Ubuntu, and neither installs Telnet by default. I'm not even certain that RHEL still has it available for manual installation.
Just because telnet was the de facto standard for remote logins on UNIX and UNIX-ish systems in the early '90's, that does not mean its use is acceptable in 2019, or 2011 for that matter.
Huawei's use of Telnet is, at this point, quite difficult to explain. Modulo the Chinese having trouble cracking and decrypting ssh traffic with key lengths over a certain threshold.
Biting the hand that feeds IT
