★ Optional side quest — moved to phantom-deep
L9 was retired from the mono chain on 2026-05-06. Your L8 flag now unlocks phantom10 directly — you can skip L9 and continue with the rest of the track. If you want the level for the badge / completion / HoF, it lives as an ephemeral phantom-deep instance: ssh [email protected] -p 2228 (use your L8 flag as the password). Same challenge, same flag, same points. Plan: four prep levels (Lock 1-4 standalone) will be added before L9 to introduce each piece — once that's in, L9 returns to the canonical chain unchanged.
Mission
Exploit a stack buffer overflow in a SUID binary (no NX, no stack canary, no PIE).
Why this matters in 2026
Memory corruption is the gateway to exploit development. Full kernel-CVE exploitation lives in the Flux track.
Mitigation era: 2026-05 · rotation policy: levels may be refreshed as CVEs are patched out of distro defaults.
Connection Terminal
Use the password forphantom9 that you captured on the previous level, then:ssh [email protected] -p 2228This level runs on its own ephemeral container — each SSH connect spawns a fresh box that disappears on disconnect.