[dreamhack] file-special-bit

nc [host][port]

chall@localhost:~$ id
uid=1000(chall) gid=1000(chall) groups=1000(chall)
chall@localhost:~$ id dream
uid=2123(dream) gid=1001(dream) groups=1001(dream)
chall@localhost:~$ ./chall flag
Your ruid : 
1000
Your euid : 
2123
DH{....}
chall@localhost:~$