Delphi : Null dereference

Null pointer dereference may occur. This may lead to incorrect behavior of the application.

The null pointer dereferencing is an operation with undefined behavior. For the implementation there are no restrictions: for example, a memory access that was not intended for the use of this program can happen (that is, when reading will be read “garbage”, and when writing a value will be written to the memory area does not belong to the program).

A null pointer dereference takes place when a pointer with NULL value is used as though it pointed to a valid memory area.

Null pointer errors are usually the result of programmer assumptions violation. Most null pointer issues result in general software reliability problems, but if an attacker can intentionally trigger a null pointer dereference, he might be able to use the resulting exception to bypass security logic or gain access to the app debugging information.

Null pointer dereferences, while common, can generally be found and corrected in a simple way. Usually they will always result in the crash of the process.