No, you don't need a shell for nul bytes to be a security
problem. Lots of C APIs won't handle nul bytes. For
example:
open( X, "> test\0me.txt" )
will succeed and will create a file called simply "test".
And if you want to send something to a shell, you need
to decide what characters to allow, rather than what
characters to not allow. /(\w[-\w.]*)/ is
a good, generic starting point.
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tye
(but my friends call me "Tye")
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Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
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<h5> <h6> <hr /> <i>
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Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
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taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
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Want more info? How to link
or How to display code and escape characters
are good places to start.
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