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Yes, -s is very bad, but I hadn't realized just how bad until you posted this.... Among the many globals that I could tweak with -s were $< $> $) and $( which should raise a huge security flag for anyone whos read perlvar. For instance, when saved as evildashs.pl, and envoked as:

% ./evildashs.pl -\<=0 -\>=0 -\(=0 -\)=0

The following code might raise some eyebrows....

#! /usr/bin/perl -wsT use strict; print "\$) = ", $), "\n"; print "\$( = ", $(, "\n"; print "\$< = ", $<, "\n"; print "\$> = ", $>, "\n"; __END__ =head1 OUTPUT $) = 0 $( = 0 $< = 0 $> = 0
I don't think this actually gives the process any new powers, but it would allow someone to execute code that was only supposed to be invoked as root.

Oh, right. I should include the obligatory link to Getopt::Std and Getopt::Long for a much better way to handle command line options.

-Blake


In reply to Re: perl -s is evil? by blakem
in thread perl -s is evil? by malloc

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