[Koha-patches] [PATCH] Bug 3652: close XSS vulnerabilities in opac-export

[Jared Camins-Esakov]

The opac-export.pl script had a number of XSS vulnerabilities relating
to its error handling.

To test:
1) Go to /cgi-bin/koha/opac-export.pl?op=export&bib=2&format=<h2>evil</h2>
   (substituting a valid biblionumber for the '2')
2) Notice that "evil" is rendered as an h2 heading.
3) Apply patch.
4) Notice that you now see the h2 tags, and they are not rendered by
   the browser.
---
 opac/opac-export.pl |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/opac/opac-export.pl b/opac/opac-export.pl
index fb8dee7..002c88e 100755
--- a/opac/opac-export.pl
+++ b/opac/opac-export.pl
@@ -32,6 +32,7 @@ my $query = new CGI;
 my $op=$query->param("op")||''; #op=export is currently the only use
 my $format=$query->param("format")||'utf8';
 my $biblionumber = $query->param("bib")||0;
+$biblionumber = int($biblionumber);
 my ($marc, $error)= ('','');
 
 $marc = GetMarcBiblio($biblionumber, 1) if $biblionumber;
@@ -41,18 +42,23 @@ if(!$marc) {
 }
 elsif ($format =~ /endnote/) {
     $marc = marc2endnote($marc);
+    $format = 'endnote';
 }
 elsif ($format =~ /marcxml/) {
     $marc = marc2marcxml($marc);
+    $format = 'marcxml';
 }
 elsif ($format=~ /mods/) {
     $marc = marc2modsxml($marc);
+    $format = 'mods';
 }
 elsif ($format =~ /ris/) {
     $marc = marc2ris($marc);
+    $format = 'ris';
 }
 elsif ($format =~ /bibtex/) {
     $marc = marc2bibtex(C4::Biblio::GetMarcBiblio($biblionumber),$biblionumber);
+    $format = 'bibtex';
 }
 elsif ($format =~ /dc/) {
     ($error,$marc) = marc2dcxml($marc,1);
@@ -61,14 +67,17 @@ elsif ($format =~ /dc/) {
 elsif ($format =~ /marc8/) {
     ($error,$marc) = changeEncoding($marc,"MARC","MARC21","MARC-8");
     $marc = $marc->as_usmarc() unless $error;
+    $format = 'marc8';
 }
 elsif ($format =~ /utf8/) {
     C4::Charset::SetUTF8Flag($marc,1);
     $marc = $marc->as_usmarc();
+    $format = 'utf8';
 }
 elsif ($format =~ /marcstd/) {
     C4::Charset::SetUTF8Flag($marc,1);
     ($error,$marc) = marc2marc($marc, 'marcstd', C4::Context->preference('marcflavour'));
+    $format = 'marcstd';
 }
 else {
     $error= "Format $format is not supported.";
@@ -78,7 +87,7 @@ if ($error){
     print $query->header();
     print $query->start_html();
     print "<h1>An error occurred </h1>";
-    print $error;
+    print $query->escapeHTML("$error");
     print $query->end_html();
 }
 else {
-- 
1.7.9.5