Offensive Lab · pro · solved in-browser (no VM needed) · 3 tiered hints
Your own disposable practice box. /usr/bin/gdb is installed SUID-root, so any debugger expression it evaluates runs with root privileges. Write /home/player/ans.txt with the single non-interactive gdb command line that, without loading init files, evaluates the inferior-call expression call (int)system("cat /root/flag.txt > /home/player/flag") and then quits. Include the gdb invocation, a -nx or -batch flag, and the -ex expression. (Authored config, graded structurally — the engine isn't run here.)
▶ Start this challengeNobody has solved this one yet — be the first clear on the leaderboard.
Open the challenge and an in-page editor appears — write your answer and tmpfs.tech grades it server-side against the same checks a real box would run. No VM, no install, no signup needed to try.
Authorized local-privilege-escalation wargames on a disposable box you own.
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Is it free? Yes — play as a guest, no signup required to start.
Do I need to install anything? No. Everything runs in your browser.
How is it graded? Automatically and deterministically — your work is checked against the exact rules the live box would apply.