Shulou(Shulou.com)06/01 Report--

In memory, the address is high and low, and when using memory, it starts from the high position of memory. But in small chunks of memory that have been defined, memory is utilized from top to bottom (that is, from low address to high address).

In the process of completing the experiment, we should pay attention to the address, memory data and numerical data are different. In numerical data, we read from left to right, but in in-memory data, it is read from right to left. For example, numerical data 0x12345678, converted to in-memory data is 0x78563412.

This experiment is actually a clever use of the string truncation null.

In the experiment, it is necessary to find out the address. As soon as the address is worked out, the experiment will be almost completed.

Stack frame layout:

Override adjacency variables:

The adjacency variable was modified successfully:

In this experiment, if your input string character is less than 1234567, the strcmp () function will return-1 strcmp will change the memory of authenticated to 0xFFFFFFFF, and if the character array overflows, the memory of authenticated will be changed to 0xFFFFFF00, which will fail verification and display incorrent password!

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