Mambo Site Server 4.0.11 allows remote attackers to obtain the physical path of the server via an HTTP request to index.php with a parameter that does not exist, which causes the path to be leaked in an error message.
index2.php in Mambo Site Server 3.0.0 through 3.0.5 allows remote attackers to gain Mambo administrator privileges by setting the PHPSESSID parameter and providing the appropriate administrator information in other parameters.