The remote host is missing an update to rsync announced via advisory USN-600-1.
A security issue affects the following Ubuntu releases:
Ubuntu 7.04 Ubuntu 7.10
This advisory also applies to the corresponding versions of Kubuntu, Edubuntu, and Xubuntu.
Details follow:
Sebastian Krahmer discovered that rsync could overflow when handling ACLs. An attacker could construct a malicious set of files that when processed by rsync could lead to arbitrary code execution or a crash.
Solution: The problem can be corrected by upgrading your system to the following package versions:
Ubuntu 7.04: rsync 2.6.9-3ubuntu1.2
Ubuntu 7.10: rsync 2.6.9-5ubuntu1.1
In general, a standard system upgrade is sufficient to effect the necessary changes.