Memories -v0.9- -recreation- - Bad

file core.dump Output:

strings core.dump | head -20 Noticed a binary name: ./bad_memories_v0.9 and a suspicious string: [!] You found a secret? Try -recreation- .

In GDB, call the overwritten function:

gdb -c core.dump (gdb) dump memory recovered.bin 0x400000 0x401000 # typical .text section But better: use volatility (if full memory dump) or memdump from /proc/pid/maps style.

Category: Reverse Engineering / Forensics (Memory Analysis) Difficulty: Medium Author: CTF Player Tooling: strings , gdb / radare2 , Volatility 3 (or 2 ), hexdump , python 1. Challenge Description "We recovered a core dump from a suspicious process. The developer said it's 'just a game', but we saw unusual memory access patterns. Find the flag hidden in the bad memories." Provided file: core.dump (or bad_memories.v0.9.core ) 2. Initial Analysis First, identify the file type: Bad Memories -v0.9- -recreation-

struct note void (*print_func)(char *); char data[56]; ; Found a pointer at 0x602010 pointing to a function 0x400c80 (normal print) and another at 0x6020a0 pointing to 0x401456 (secret function).

gdb -c core.dump ./bad_memories_v0.9 (gdb) info registers (gdb) x/20gx $rsp Look for a struct: file core

However, this core dump is process-only. Use elfutils :

gdb -c core.dump Inside GDB:

CTFBad_Memories_Unleash_Secret_Recreation To recreate the vulnerability locally:

Check if that note was freed: