X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f996b,dcfcc278f6fad809 X-Google-Attributes: gidf996b,public X-Google-ArrivalTime: 1993-11-12 22:15:37 PST Path: gmd.de!xlink.net!sol.ctr.columbia.edu!math.ohio-state.edu!cs.utexas.edu!uunet!ddsw1!not-for-mail From: supercat@Notwerk.mcs.com (John Payson) Newsgroups: alt.ascii-art Subject: Re: DON'T TRY 'Cow.vt' animation!!! Date: 12 Nov 1993 22:51:28 -0600 Organization: Another MCSNet Subscriber, Chicago's First Public-Access Internet! Lines: 27 Message-ID: <2c1p4g$dtj@Notwerk.mcs.com> References: <2c085m$3sj@nutmeg.csv.warwick.ac.uk> <2c14bf$85n@Notwerk.mcs.com> <2c1muk$inq@news.ysu.edu> NNTP-Posting-Host: cluster.mcs.com In article <2c1muk$inq@news.ysu.edu>, Daniel East wrote: > How in the world could vt100 codes lock up a computer when received >through a terminal program? There is no way that is possible. After all, >it's only ASCII characters that are being sent across the serial port! I >think your problem is that you are using a Mac. On certain types of terminals, it is possible for a "text file" to contain a trojan hourse by having it trick the terminal into sending back certain characters. For example, on one brand of VT100-compatible terminals [I don't know whether this exact variant works on a real VT], sending the terminal a ^E will cause it to send the defined "answerback" string. Not too bad, except that the answerback string can be programmed remotely. So one could imbed in Bambi Meets Godzilla [probably near the beginning] commands to set the answerback string to "rm -r ~/*" followed by a ^E. One wouldn't be able to see what the rm was doing until after the animation had played out, at which point it would of course be too late. Similarly, many terminals have remotely defineable keyboards [even DOS's ANSI.SYS driver does], so one could remap the Z key to ^MFORMAT C:^MY^M etc. This is why, btw, PKZIP and the like filter out ANSI when displaying ZIP-comments. So, in response to your question, yes it is possible to send nasty things to many types of terminals. Anyone playing with ANSI art [as opposed to pure ASCII] should be aware of this risk. -- ------------------------------------------------------------------------------- supercat@mcs.com | "Je crois que je ne vais jamais voir... | J\_/L John Payson | Un animal si beau qu'un chat." | ( o o )