<ul><li>The PicoCTF 'Function Overwrite' CTF Writeup demonstrates how to exploit an arbitrary memory write vulnerability in a binary program.</li><li>By overwriting the check() pointer with the address of the easy_checker() function, the program's security check can be bypassed.</li><li>The write is achieved by underflowing the fun variable, which allows arbitrary memory write beyond the buffer boundaries.</li><li>The writeup provides both a manual calculation method and a brute-force method to determine the necessary offsets for the exploit.</li></ul>

PicoCTF - “Function Ovewrite” CTF Writeup

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