The remote host is missing updates announced in advisory CLA-2004:800.
lftp[1] is a command-line file transfer program which supports many protocols.
Ulf Härnhammar reported[2] two buffer overflow vulnerabilities[3] in the lftp program. An attacker could prepare a directory on a server which, if accessed with a vulnerable lftp with the ls or rels command, could cause arbitrary code to be executed on the client.
Solution: The apt tool can be used to perform RPM package upgrades by running 'apt-get update' followed by 'apt-get upgrade'