OverTheWire FormulaOne Level 5 → 6 tutorial!!

Login

ssh formulaone5@formulaone.labs.overthewire.org -p 2232
# password: (would normally be from Level 4 → 5)

Task

Progress from formulaone5 to formulaone6. In theory, we’d exploit the binary left behind (nemo1.c) to gain access.

Reality Check

This is where the FormulaOne wargame effectively ends.

The provided nemo1.c contains a runtime guard:

if((long)&buf2 > (long)&mfptrr) {
    printf("[!] Sorry, it's unlikely you can exploit this with your version of gcc.\n");
    exit(1);
}

This stack layout check ensures that on modern GCC/glibc, the exploit path is closed. The vulnerable arrangement only existed on very old GCC versions (circa 2005).

As a result:

• On current OverTheWire servers, the exploit is not reachable.
• The “Level 6” login user does not exist → FormulaOne officially stops here.

Theory

The intended exploit (if compiled under older GCC) would involve:

1. Leveraging func1 + environment variables to overflow into stack variables.
2. Overwriting the function pointer mfptrr.
3. Redirecting execution flow to attacker-controlled code.

This kind of vulnerability is classic in early buffer overflow challenges, but modern compilers + protections broke the setup.

Solution

👉 There is no playable solution on today’s FormulaOne servers.

The official stance is: FormulaOne ends at Level 5.

So the “solution” for 5 → 6 is simply to acknowledge that we’ve reached the natural end of the wargame.

Conclusion

That’s it — FormulaOne complete 🎉

• Levels 0 → 4 gave us fun exploitation challenges (sockets, race conditions, shared memory, stack smashing).
• Levels 5 → 6 serve more as a historical artifact, showing how compiler behavior used to be exploitable.

Although a bit anti-climactic, it’s a reminder: exploits are fragile and evolve with toolchains.

Next Adventures

If you enjoyed FormulaOne, consider moving on to:

• Maze (advanced binary exploitation)
• Utumno (heap tricks & shellcode)
• Narnia (classic overflows)

Thanks for reading!

Until next time — Otsumachi!! 💖☄️✨