oss-sec mailing list archives

Re: Telnetd Vulnerability Report


From: Eddie Chapman <eddie () ehuk net>
Date: Tue, 24 Feb 2026 23:18:39 +0000

On 24/02/2026 20:33, Solar Designer wrote:
On Tue, Feb 24, 2026 at 05:05:58AM -0500, kf503bla () duck com wrote:
Who uses telnet anyway? It's deprecated. Everyone uses ssh for any kind of remote access.

Indeed.  Yet:

Quite many people surely do still use a telnet client to access various
older/smaller devices

Yes. I would hazard a guess that the largest cohort of devices running a telnet server are enterprise switches, gateways & routers. So many times over the years I've been surprised to find a switch I'm configuring has a telnet as well as the obligatory http(s) server available for the admin to login via.

Albeit to a lesser extent these days, and more likely BusyBox telnetd than InetUtils. But switches are one of the most likely pieces of kit to be forgotten about and left running for 10+ years in a closet without a firmware update. There are a LOT of old switches running out there.


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