The copy_symlink function in rsnapshot 1.2.0 and 1.1.x before 1.1.7 changes the ownership of files that a symlink points to rather than the symlink itself, which allows local users to obtain access to arbitrary files.
http://www.rsnapshot.org/security/2005/001.html
http://www.gentoo.org/security/en/glsa/glsa-200504-12.xml
http://securitytracker.com/id?1013674