The remote host is missing an update to turba2 announced via advisory DSA 1507-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201507-1

Peter Paul Elfferich discovered that turba2, a contact management component for horde framework did not correctly check access rights before allowing users to edit addresses. This could result in valid users being able to alter private address records. For the stable distribution (etch), this problem has been fixed in version 2.1.3-1etch1. For the old stable distribution (sarge), this problem has been fixed in version 2.0.2-1sarge1. For the unstable distribution (sid), this problem has been fixed in version 2.1.7-1. We recommend that you upgrade your turba2 package.