pwnhard

Bottoms Up

miptctf

Custom stack-based VM with 32-bit stack pointer. POP has no underflow check, allowing 2^32 wraparound to write past stack bounds. Exploit leaks PIE/libc, bypasses canary by skipping check, builds ROP chain for system("/bin/sh").

$ ls tags/ techniques/

integer_overflow ret2libc pie_bypass rop custom_vm canary_bypass libc_identification stack_underflow 32bit_wraparound

pie_leakvm_stack_underflow32bit_integer_wraparoundrop_chain_constructionlibc_leakcanary_bypass_via_return_skip

Analysis

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$ python3 exploit.py --target 192.168.1.1 --port 8080
[*] Connecting to target...
[+] Shell obtained!

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