Security: Prevent leading zeroes in ipv4 octets

This prevents prevents octal ipv4 addresses from being incorrectly
handled by not supporting leading zeroes.

010.0.0.1 was incorrectly treated as 10.0.0.1, rather than 8.0.0.1

More information is availabe here:
https://blog.urth.org/2021/03/29/security-issues-in-perl-ip-address-distros/

Lite.pm

@@ -181,7 +181,7 @@ sub _pack_ipv4 {
     my @nums = split /\./, shift(), -1;
     return unless @nums == 4;
     for (@nums) {
-        return unless /^\d{1,3}$/ and $_ <= 255;
+        return unless /^\d{1,3}$/ and !/^0\d{1,2}$/ and $_ <= 255;
     }
     pack("CC*", 0, @nums);
 }

t/base.t

@@ -8,7 +8,7 @@
 use Test;
 use strict;
 $|++;
-BEGIN { plan tests => 39 };
+BEGIN { plan tests => 42 };
 use Net::CIDR::Lite;
 ok(1); # If we made it this far, we are ok.
 
@@ -133,3 +133,14 @@ ok(join(', ', @list_short_range), '10.0.0.1-2, 10.0.0.5');
 })->list_short_range;
 ok(join(', ', @list_short_range), '10.0.0.250-255, 10.0.1.0-20, 10.0.1.22, 10.0.2.250-255, 10.0.3.0-255, 10.0.4.0-255, 10.0.5.0-8');
 
+
+# Tests for vulnerability: https://blog.urth.org/2021/03/29/security-issues-in-perl-ip-address-distros/
+eval { Net::CIDR::Lite->new("010.0.0.0/8") };
+ok($@=~/Can't determine ip format/);
+
+my $err_octal = Net::CIDR::Lite->new;
+eval { $err_octal->add("010.0.0.0/8") };
+ok($@=~/Can't determine ip format/);
+
+eval { $err_octal->add("10.01.0.0/8") };
+ok($@=~/Can't determine ip format/);