Some doubts about security

Some questions about security
Java for network and distributed environments must be protected from virus intrusion. Java does not support pointers, and all access to memory must be implemented through the object's instance variables, which prevents programmers from using "Trojan" Trojans and other deceptive means to access the object's private Members , but also avoids errors that are easily generated by pointer manipulation.

See here I have some do not understand, ' Trojan horse and other deception means to access the private members of the object ' is how a principle, do not know PHP has this disadvantage. Still, this is a previous loophole. Java PHP

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Eval is evil that's how it came from.

Actually, it's just an alibi, there is nothing.
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This should be a mechanism within the language. But I don't really understand the meaning of that sentence.

You instantiate an object that is in an address in memory, and in CPP you can point directly at the address with a pointer. But what's the use? So I can access the private members of that object?

So in PHP or Java, I can clone that object, or directly create a reference to that object. In my opinion, this is no different from pointing the pointer directly to that object.
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PHP and Java are very similar in OOP

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