in reply to taint mode perplexities

At this site, the following was written on March 25, 2006:
I have been reading up on web security and I am getting paranoid. I operate under taint mode - although I must confess to being a little in the dark as to what that means. I am using the following code in order to filter input from a form. CODE $TEST =~ s/[^a-zA-Z0-9@\/.,: ]//g; It works as expected but I am trying to make it as secure as possible +and found that if a user enters '<SCRIPT>' into a form field it treats it +as a Java Code and it is not filtered. I assume that I could follow this wi +th some other code and do some harm. I need to avoid this security hole and ob +viously I could check for the word '<SCRIPT>' in STDIN. Is there a better way of doing this and what other holes should I be a +ware of? Keith

s''(q.S:$/9=(T1';s;(..)(..);$..=substr+crypt($1,$2),2,3;eg;print$..$/

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Re^2: taint mode perplexities
by hossman (Prior) on Oct 07, 2006 at 03:04 UTC

    In a really odd twist, I note that the orriginal title of this node as "audio program" ... while "audiopro" is the nick used by "Kieth" on tek-tips.com