From mboxrd@z Thu Jan 1 00:00:00 1970 From: paul.winalski@gmail.com (Paul Winalski) Date: Sun, 12 Mar 2017 14:33:36 -0400 Subject: [TUHS] attachments: MIME and uuencode In-Reply-To: <201703121813.v2CIDtRH099094@tahoe.cs.Dartmouth.EDU> References: <201703121813.v2CIDtRH099094@tahoe.cs.Dartmouth.EDU> Message-ID: On 3/12/17, Doug McIlroy wrote: > Allowing more or less arbitrary attachments was a real convenience. > But allowing such stuff to serve as the message proper was > dubious at best. Not only did it require recipients to obtain > special software to read some messages; it also posed a > security threat. > > I still use mailx precisely because it will only display plain text. Back in the day plain ASCII wasn't really secure, either. There were bugs in the firmware of the VT100 and other smartish terminals that would cause strange behavior if certain malformed control sequences were received. For example, causing the bell (actually a loud beep) to sound continuously until the terminal was power-cycled. There was one sequence that stored bad data into the user preferences area of the EPROM. That bricked the terminal by causing it to go into a reset/crash loop. DEC ended up modifying VMS Mail to filter out ASCII control characters by default when it displayed email messages. You could still display the unfiltered text, but you had to explicitly ask for that to be done. -Paul W.