secure_keymanager

In this challenge, there is a double free vulnerability by which we can mount the fastbin dup attack to get an arbitrary write into GOT table. Then, using a format string attack, we can leak a libc address, and finally execute system("/bin/sh") by overwriting a GOT entry. This is an interesting heap exploitation challenge to learn bypassing protections like NX, Canary, and ASLR in x86_64 binaries.