NetBSD
 * getch in -lcurses cannot be set nonblocking in older releases
   leading to the curses gui being unfunctional.

OpenBSD 64bit arch
 * OpenBSD on 64bit archs provides unnecessary padding in the
   data provided by sysctl leading to a segfault if more than
   one interface is configured. This is not a bug of bmon but
   rather of OpenBSD.

netstat input method
 * vulnerable to escaping attacks. This is a feature not a bug,
   the path to netstat will stay configureable, do not install
   bmon suid root. The same issue applies to key bindings.