From e94a7e34f330082fd485309fc08250aaf3645633 Mon Sep 17 00:00:00 2001
From: David Cook <dcook@prosentient.com.au>
Date: Tue, 20 Aug 2024 00:54:38 +0000
Subject: [PATCH] Bug 37681: Fix XSS in staff interface item URLs on detail
 page

This patch uses Javascript objects and safe sinks to prevent XSS
in the item URLs on the staff interface detail page.

It also makes sure those URLs don't get double-escaped. Yippee!

Test plan:
0. Apply the patch
1. Add/edit an item with the following URL:
http://prosentient.com.au?q=http%3A%2F%2Fprosentient.com.au
2. Add/edit a different item with the following URLs:
http://prosentient.com.au?q=http%3A%2F%2Fprosentient.com.au |
http://prosentient.com.au?q=http%3A%2F%2Fprosentient.com.au
3. Go to the staff interface detail page
4. Notice that the URLs are not double-encoded!
5. Try out a malicious payload (talk to QA/security about this)
6. Confirm that the malicious payload fails to execute the XSS
7. Celebrate!

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
---
 .../tables/items/catalogue_detail.inc         | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/koha-tmpl/intranet-tmpl/prog/en/includes/html_helpers/tables/items/catalogue_detail.inc b/koha-tmpl/intranet-tmpl/prog/en/includes/html_helpers/tables/items/catalogue_detail.inc
index b97b89a99b..c3df0736f0 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/includes/html_helpers/tables/items/catalogue_detail.inc
+++ b/koha-tmpl/intranet-tmpl/prog/en/includes/html_helpers/tables/items/catalogue_detail.inc
@@ -629,10 +629,12 @@
                     let nodes = '';
                     if ( row.uri.split(' \| ').length > 1 ) {
                         row.uri.split(' \| ').forEach((uri, i) => {
-                            nodes += '<a href="%s">%s</a><br/>'.format(escape_str(uri), escape_str(uri));
+                            let node = safe_link(uri,uri);
+                            nodes += node.outerHTML + "<br>";
                         });
                     } else {
-                        nodes += '<a href="%s">%s</a><br/>'.format(escape_str(row.uri), escape_str(url_link_text));
+                        let node = safe_link(row.uri,url_link_text);
+                        nodes += node.outerHTML;
                     }
                     return nodes;
                 }
@@ -846,5 +848,18 @@
 
         return items_table;
     }
+    function safe_link(uri,link_text) {
+        let node = document.createElement('a');
+        let url_str = '#';
+        try {
+            const safe_url = new URL(uri);
+            url_str = safe_url.href;
+        } catch (e) {
+            //console.error('Invalid URL:', e);
+        }
+        node.setAttribute('href',url_str);
+        node.textContent = link_text;
+        return node;
+    }
 </script>
 [% END %]
-- 
2.39.5