The remote host is missing an update to zope-ldapuserfolder announced via advisory DSA 2096-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202096-1

Jeremy James discovered that in zope-ldapuserfolder, a Zope extension used to authenticate against an LDAP server, the authentication code does not verify the password provided for the emergency user. Malicious users that manage to get the emergency user login can use this flaw to gain administrative access to the Zope instance, by providing an arbitrary password. For the stable distribution (lenny), this problem has been fixed in version 2.9-1+lenny1. The package no longer exists in the upcoming stable distribution (squeeze) or the unstable distribution. We recommend that you upgrade your zope-ldapuserfolder package.