Notice how in my first test, I called sh? Some OSes (these examples were from a MacOS X box) use bash for sh.

You should run the tests and check if you're vulnerable. Don't just think 'oh, it won't happen to me, I'm using ksh', as perl may still send to a vulnerable sh:

sh-3.2$ ksh
$ set -o emacs
$ env x='() { :;}; echo vulnerable' ksh -c "echo this is a test"
this is a test
$ env x='() { :;}; echo vulnerable' perl -e 'system "echo test;"'
vulnerable
test

[download]

In reply to Re^2: The importance of avoiding the shell by jhourcle
in thread The importance of avoiding the shell by jhourcle

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.