The challenge has 3 files:
and the libc
checking the binary for protection:
[*] '/home/cheepsss/Documents/picoctf/heres_a_libc/vuln_patched'
Arch: amd64-64-little
RELRO: Partial RELRO
Stack: No canary found
NX: NX enabled
PIE: No PIE (0x400000)
RUNPATH: b'.'
The stack is not executable so a return to libc is needed.
When I tried to run the binary this error appeared:
./vuln
Inconsistency detected by ld.so: dl-call-libc-early-init.c: 37: _dl_call_libc_early_init: Assertion `sym != NULL' faile
To fix it:
I installed pwninit - https://github.com/io12/pwninit and the additional dependencies