PHP remote file inclusion vulnerability in top/list.php in phpBB TopList 1.3.8 and earlier allows remote attackers to include arbitrary files via the returnpath parameter.
The gen_rand_string function in phpBB 2.0.19 uses insufficiently random data (small value space) to create the activation key ("validation ID") that is sent by e-mail when establishing a password, which makes it easier for remote attackers to obtain the key and modify passwords for existing accounts or create new accounts.