use strict;
use warnings;

use XML::XPath;
use XML::XPath::XMLParser;

my $data_file = "./nvdcve-2.0-2008.xml";

my $cve_id = 'CVE-2008-3763';
my $query = "/nvd/entry[@id = $cve_id]";

my $xp = XML::XPath-> new(filename => "$data_file");

foreach my $cve_entry ($xp->findnodes($query)) {

		my $AV = $cve_entry->find('//entry/vuln:cvss/cvss:base_metrics/cvss:access-vector');
		my $AC = $cve_entry->find('//entry/vuln:cvss/cvss:base_metrics/cvss:access-vector');
		my $AV = $cve_entry->find('//entry/vuln:cvss/cvss:base_metrics/cvss:access-complexity');
		# etc...
}