xpdf PDF viewer client earlier than 0.91 allows local users to overwrite arbitrary files via a symlink attack.
http://www.securityfocus.com/bid/1624
http://www.redhat.com/support/errata/RHSA-2000-060.html
http://www.calderasystems.com/support/security/advisories/CSSA-2000-031.0.txt