PHP file inclusion vulnerability in php121db.php in PHP121 Instant Messenger 2.2 allows remote attackers to execute arbitrary PHP code via a UNC share pathname or a local file pathname in the php121dir parameter, which is accessed by the file_exists function.

SQL injection vulnerability in php121language.php in PHP121 1.4 allows remote attackers to execute arbitrary SQL commands and execute arbitrary code via the sess_username variable, as set by the php121un HTTP COOKIE parameter, which is used in multiple files including php121login.php. NOTE: the code execution occurs because the SQL query results are used in an include statement.