SIPP 1.8.3 suffers from a remote php inclusion vulnerability in spip_login.php3.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/45377/SPIP-1.8.3.txt
Source: https://packetstormsecurity.com/files/45377/SPIP-1.8.3.txt.html