I have a research-oriented database, online, accessible via my own web interface and open to public use. The application is set up to allow read-only access to the database, the CGI script is hosted on a linux server, and the script is definitely not set as setuid. I am not allowing any use of nested executable code inside the regex, via the following sort of rules during the parsing of the query:

return "ERROR: For security and bandwidth reasons, query may not conta
+in pure wildcards." if $SR_query =~ m/^[( ]*\.\s*(?:(?:\{\s*\d+\s*,?\
+s*\d*\s*})?|[*+?]*)[) ]*$/;
return "ERROR: Regex containing code disallowed." if $SR_query =~ m[\(
+\?\??\{];

[download]

Beyond these fundamental/basic protections against potential malicious actors, is there anything I might be blindly walking into by unleashing this capability in my website?

I have had to run a rather complicated subroutine on the query itself to prevent taint from objecting to it--even though the code is never "executed" other than being inserted into a m// to run against text drawn from the database prior to formatting the results for return to the browser. But this is a small price to pay for the very useful functionality of having regex-capable searches on the database.

Blessings,

~Polyglot~

In reply to Allowing regex entries in web form to search database: Risks or gotchas? by Polyglot

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.