Mike O'Connor discovered that the default installation of Horde3 on Debian includes an administrator account without a password. Already configured installations will not be altered by this update.
The old stable distribution (woody) does not contain horde3 packages.
For the stable distribution (sarge) this problem has been fixed in version 3.0.4-4sarge1.
For the unstable distribution (sid) this problem has been fixed in version 3.0.5-2
We recommend that you verify your horde3 admin account if you have installed Horde3.
MD5 checksums of the listed files are available in the original advisory.