SQL injection vulnerability in include/functions_trackbacks.inc.php in Serendipity 1.6.2 allows remote attackers to execute arbitrary SQL commands via the url parameter to comment.php.
https://www.htbridge.com/advisory/HTB23092
https://github.com/s9y/Serendipity/commit/87153991d06bc18fe4af05f97810487c4a340a92#diff-1
https://exchange.xforce.ibmcloud.com/vulnerabilities/75760
http://www.securitytracker.com/id?1027079
http://www.securityfocus.com/bid/53620
http://secunia.com/advisories/49234
http://blog.s9y.org/archives/241-Serendipity-1.6.2-released.html