CgiUserConfigEdit in BackupPC 3.1.0, when SSH keys and Rsync are in use in a multi-user environment, does not restrict users from the ClientNameAlias function, which allows remote authenticated users to read and write sensitive files by modifying ClientNameAlias to match another system, then initiating a backup or restore.
bugs.debian.org/cgi-bin/bugreport.cgi?bug=542218
osvdb.org/57236
secunia.com/advisories/36393
secunia.com/advisories/37161
bugzilla.redhat.com/show_bug.cgi?id=518412
www.redhat.com/archives/fedora-package-announce/2009-October/msg00694.html
www.redhat.com/archives/fedora-package-announce/2009-October/msg00729.html