I don't shell user input, but I don't check input if it is only for DB insertion.

That's fine, but you should consider data coming out of the database to be tainted. I believe there's an option that can be passed to connect when you open the db handle that will cause data coming from the db to be marked as tainted. Then if you try to do anything insecure with it, you'll get an error relevant to what you were trying to do, so you know what your checking needs to ensure.

Further, what's to stop somebody from passing me an enormous file that crashes my server?

Bandwidth. If they have enough bandwith to send you a file large enough to crash your server, there are a dozen other ways they can DOS you. Set a limit if you're worried about it (other posts in the thread tell you how), but I doubt it will be a real issue. 

$;=sub{$/};@;=map{my($a,$b)=($_,$;);$;=sub{$a.$b->()}}
split//,".rekcah lreP rehtona tsuJ";$\=$ ;->();print$/

[download]

In reply to Re: CGI File Upload Security by jonadab
in thread CGI File Upload Security by Anonymous Monk

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.