varnishadm or varnish in weird state

[Dridi Boukelmoune]

> $ sudo varnishadm backend.list
> PONG 1503057040 1.0

Hello,

This is a known bug, fixed a while ago:

https://github.com/varnishcache/varnish-cache/issues/2010
https://github.com/varnishcache/varnish-cache/pull/2019

You should upgrade to 4.1.8, your version has a major vulnerability
and known bugs:

https://varnish-cache.org/security/VSV00001.html

Cheers