Reliable Penguin

I just ran across this method for remotely forcing a gateway to flush an
arp entry when you move IP addresses around.

1) Download/install "arping" from the following URL. System will need
libnet-devel and libpcap:
http://www.habets.pp.se/synscan/programs.php?prog=arping

2) Run this command: arping -c 1 -S a.a.a.a b.b.b.b

Where "a.a.a.a" is the IP you've moved, and "b.b.b.b" is the gateway IP.
Run this from the server to which you moved the IP. This should force
the gateway to flush its arp entry for that source IP.

Below is the quick fix for the Plesk-Horde vulnerability.

Manually apply a patch to the Horde Permission's User Interface code to
"remove" the "All Authenticated Users" option from the HTML form:

A quick fix to hide this setting in the UI code is to add HTML comments
("<! --" ... "-->") around the "All Authenticated Users" options in the
HTML form. Basically, it is to add "<! --" at line 63 and "-->" at
(original) line 81 in /usr/share/psa-horde/templates/shares/edit.inc