I've distilled all this advice this as best I can. 
============
something.lib
============
sub safer {
    my $hash = shift;
    my %safer;
    while (my ($k, $v) = each %$hash) {
        s/\\//g         for $k, $v;
        s/0x00//g       for $k, $v;
        s/0x08//g       for $k, $v;
        s/0x09//g       for $k, $v;
        s/0x0a/\n/g     for $k, $v;
        s/0x0d/\r/g     for $k, $v;
        s/"/\\"/g       for $k, $v;
        s/%/\\%/g       for $k, $v;
        s/'/\\'/g       for $k, $v;
        s/_/\_/g        for $k, $v;

        $safer{$k} = $v;
    }
    return %safer;
}

================
something.cgi...
================
use warnings;
use strict;
use CGI;
use CGI::Carp;

print "Content-type: text/html\n\n";

# marker
my $cgi = CGI->new();

$cgi->param;
my %params;

for my $name ($cgi->param) {
    my @values = $cgi->param($name);
    $params{$name} = @values > 1 ? \@values : $values[0];
}

%params=safer(\%params);
# marker

for my $param (keys %params) {
    print "$param: $params{$param}<br>"
}

[download]
The stuff between the two markers will replace the existing 
sub main
{
        my $cgi = CGI->new();
        my %params = $cgi->Vars();

[download]
... in the existing scripts. This is running under mod-perl (w/ regcooker). Are there any "gotchas" I should be aware of here? Thanks to all you monks for all your help!

In reply to Re^2: Escaping %params by DaisyLou
in thread Escaping %params by DaisyLou

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.