Bug 34023: Prevent HTML injection in "back to results" link from search page
authorMichał Górny <mgorny@gentoo.org>
Fri, 16 Jun 2023 14:16:37 +0000 (16:16 +0200)
committerTomas Cohen Arazi <tomascohen@theke.io>
Thu, 3 Aug 2023 19:40:02 +0000 (16:40 -0300)
commit863d8fed15411b03adfe2105fc7d4b2321fea0b9
tree024e049892cee7d021dc96c0e1280ec57f02de81
parente7e5a54dc897a3fa08722ce268862ff2aecae23e
Bug 34023: Prevent HTML injection in "back to results" link from search page

It is possible inject raw HTML into the "Back to search results" link by leading the user to a search with specially crafted URL.

For example, using the demo instance:

1. Visit https://koha.adminkuhn.ch/cgi-bin/koha/opac-search.pl?idx=&q=test&weight_search=1&%22%3Etest%3Ca%20foo=%22

2. Refresh the page (for some reason, "back to results" doesn't appear unless I do that at least once).

3. Click any result.

Note that the result page now contains:

  <a href="opac-search.pl?idx=&amp;q=test&amp;weight_search=1&amp;">test<a foo=%22" title="...

i.e. `">test<a ...` was successfully injected into the HTML.

I'm attaching a quick patch I've used to patch up our instance.  It just indiscriminately URI-escapes all parameter keys.  I didn't decode them back since as far as I understand all valid keys do not contain special characters.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
opac/opac-search.pl