[blackflame7000]

The text-segment of the code containing the machine instructions is in read-only memory. You won't be able to overflow a heap variable with the intention of writing to the text-segment of memory without causing a segfault.

[0x0]

But with ROP, there's usually no need to write into the text-segment to execute arbitrary code.

[blackflame7000]

In order to do ROP, you need to chain together gadgets of code segments which means you need to be able to see the source code/binary. This doesn't reveal any information about the call stack nor the available libraries to chain together ROP. And that's if stack canaries haven't screwed things up already.