October Season: Close the Door
Three boxes, three doors left open on the way out — a passwordless-root sudoers backdoor, a SUID-root shell in the weeds, and an SSH config wide open with a stranger's key in it. Find each foothold, close it without breaking the legitimate access around it, and recover what they left behind. Sandboxes you fully control. Defensive hardening only.
Archived season — playable for practice, no leaderboard points. Official write-ups are open.
The Rule They Left Behind
security · sudo · sudoers
SUID in the Weeds
security · suid · privilege-escalation
Close the Door
security · ssh · hardening
SUID in the Weeds
275 pts · decays to 110 · +50 first bloodSomeone planted a SUID-root copy of a shell in a hidden maintenance directory — an executable that runs as root no matter who launches it, a classic privilege-escalation foothold. Hunt it down among the box's legitimate SUID binaries, record its path, neutralize it, and recover the receipt beside it. Full root on an isolated box.
The live sandbox for this challenge isn't available yet — the brief is open.
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Submit flag
Complete every objective in the lab and use Verify & grade, then submit the flag from that same box here.
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Archived — solves are for practice, not the leaderboard.
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