Don't trust the cache :Exposing Web cache vulnerabilities

Some airlines use caches for their user sat connection because bandwidth is so limited. I know because their squid server sent me an error trace once and I got a lot of insight into the configuration. I wonder if it still performs well now that nearly all connections use TLS.

الحمدلله و الصلاة و السلام على رسول الله

translates to

Praise be to Allah and peace and blessings be upon the Messenger of Allah

What is that doing in a tech article? Is this the cache vuln?