この大会は2020/11/28 11:00(JST)～2020/11/29 23:00(JST)に開催されました。
今回もチームで参戦。結果は50点で710チーム中234位でした。
自分で解けた問題をWriteupとして書いておきます。
Welcome (reverse)
$ ssh welcome@18.176.232.130 The authenticity of host '18.176.232.130 (18.176.232.130)' can't be established. ECDSA key fingerprint is SHA256:2nRBoRgG1pfAq1PJG4EYWpdTcr8ubnkyQ7pUIxv74fI. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '18.176.232.130' (ECDSA) to the list of known hosts. welcome@18.176.232.130's password: Welcome to Ubuntu 20.04.1 LTS (GNU/Linux 5.4.0-1029-aws x86_64) * Documentation: https://help.ubuntu.com * Management: https://landscape.canonical.com * Support: https://ubuntu.com/advantage System information as of Sat Nov 28 02:30:02 UTC 2020 System load: 0.01 Processes: 168 Usage of /: 25.6% of 7.69GB Users logged in: 1 Memory usage: 20% IPv4 address for eth0: 172.31.25.82 Swap usage: 0% 0 updates can be installed immediately. 0 of these updates are security updates. The programs included with the Ubuntu system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. The programs included with the Ubuntu system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. Last login: Sat Nov 28 02:29:58 2020 from 115.68.208.205 $ ls
ASCII ARTの汽車が走っていった。
$ cat flag tac: failed to open 'galf' for reading: No such file or directory
単語ごとに逆になるっぽい。lsコマンドは"sl"ということだったらしい。
$ sl flag $ tac galf hitcon{!0202 ftcnoctih ot emoclew}
hitcon{!0202 ftcnoctih ot emoclew}
