zdog: I have to disagree with your assessment on this one. Different people have different styles of communication and learning and merlyn's style is simply one of many. In this case, his title was "Web Security" and here's what I consider to be the truly relevant paragraph:
In other words, not only was unchecked data from a form field (presumably from a pop-up menu or radio button) being used directly in an eval, but quite helpfully, the syntax errors were being sent back to the browser to help you refine your breakin! (And I looked hard for some sort of screening or vetting of the $p_type value, and there was none.)
In short, merlyn presented some poor Perl code and explained to us exactly why it's a problem. That seems, in my mind, to be a reasonable meditation. Of course, he didn't go step by step through various ways we might exploit this, but there's a certain level of minimum knowledge assumed on the part of the reader. Myself, I like to assume little on the part of the reader so I tend to explain things more in depth (like now), whereas merlyn appears to assume a more knowledgeable audience. Thus, he is often accused of being arrogant or rude and I'm accused of pandering. No matter how one approaches things, some people will be put off :)
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