Michael Marek discovered that the Horde web application framework performs insufficient input sanitising, which might lead to the injection of web script code through cross-site scripting.
The old stable distribution (woody) does not contain horde2 packages.
For the stable distribution (sarge) this problem has been fixed in version 2.2.8-1sarge3.
The unstable distribution (sid) does no longer contain horde2 packages.
We recommend that you upgrade your horde2 package.