Bug 19052 - XSS Flaws in vendor search page

Bug 19052 - XSS Flaws in vendor search page

1. Hit /cgi-bin/koha/acqui/booksellers.pl
2. Enter <IFRAME SRC="javascript:alert('XSS');"></IFRAME> vendor search box.
3. Notice the iframe is executed.
4. Apply patch.
5. Reload page, and enter iframe again on vendor search box.
6. Notice it is no longer executed.

Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
(cherry picked from commit d8b1c8fc7d9ba254b1e71d1501abfae4102e7eea)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>