To "fix" this would fix more existing code than it would break existing code. In fact, this sounds like something that should be in a CERT advisory not something to be kept for backward compatability.

The amount of code that intends to take advantage of this behavior is tiny. The amount of code at risk because of this behavior is huge.

My choice would be to require 

    use open IN => ":magic";

[download]
to get the current (hopefully soon to be "old") behavior rather than sane behavior.

And tainting isn't much of a solution. It is very easy to see situations where privileged users run a not-tainted script that looks up filenames from directories where less-privileged users can create files. For any reasonable program, this is a safe thing to do and so is not something people worry about or use "tainting" to protect against.

                - tye

In reply to Re^4: TIMTOWDTDI, obfu and analyzis of code (<> broken) by tye
in thread TIMTOWDTDI, obfu and analyzis of code by zby

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.