Really bad thing could happen even outside '(?{...})' constructs.

For example (this is something totally innocent, but you get the idea): 

use strict;
my $str  = 'abcadefaghi';
my $pat  = qr/(a.)/;
my $repl = 'system dir ';
$str =~ s/$pat/$repl/eeg;

[download]

Of course you could try to filter out all system, exec and backticks, but that is only solving a small part of the possible problems as anything inside the $repl-variable gets run as a perl-program.

CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law

In reply to Re: Re: Re: $1 in variable regex replacement string by CountZero
in thread $1 in variable regex replacement string by dvergin

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