The WDDX deserializer in the wddx extension in PHP 5 before 5.2.1 and PHP 4 before 4.4.5 does not properly initialize the key_length variable for a numerical…

The WDDX deserializer in the wddx extension in PHP 5 before 5.2.1 and PHP 4 before 4.4.5 does not properly initialize the key_length variable for a numerical key, which allows context-dependent attackers to read stack memory via a wddxPacket element that contains a variable with a string name before a numerical variable.