Bug 36520: Prevent SQL injection in GetPreparedLetter

Bug 36520: Prevent SQL injection in GetPreparedLetter

Actually in _get_tt_params

The following query will delay the response

SELECT `me`.`biblionumber`, `me`.`frameworkcode`, `me`.`author`, `me`.`title`, `me`.`medium`, `me`.`subtitle`, `me`.`part_number`, `me`.`part_name`, `me`.`unititle`, `me`.`notes`, `me`.`serial`, `me`.`seriestitle`
, `me`.`copyrightdate`, `me`.`timestamp`, `me`.`datecreated`, `me`.`abstract`
  FROM `biblio` `me`
WHERE `biblionumber` = '1) AND (SELECT 1 FROM (SELECT(SLEEP(6)))x)-- -'
ORDER BY field( biblionumber, 1 ) AND (
    SELECT 1
      FROM
    SELECT SLEEP( 6 ) x
   ) -- - )

To test
1/ Add some items to your cart in the opac
2/ Choose send cart
3/ Open firefox developer tools and switch to the network tab
4/ Send cart
5/ In the network tab, find the post request and choose copy as curl
6/ Edit the curl command to add )+AND+(SELECT+1+FROM+(SELECT(SLEEP(6)))x)--+-  to the bib_list parameter
7/ Run the curl notice it takes a long time to respond, if you want to check run the curl without the above part added
8/ Apply the patch and restart plack
9/ Run the modified curl and notice no longer the slow down
10/ Test in browser and make sure the basket is still sent

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
(cherry picked from commit 0b3c98b0ba01ea5c886ecfe8eef174b5b7c6ec25)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>