The dcopidlng script in KDE 3.2.x and 3.3.x creates temporary files with predictable filenames, which allows local users to overwrite arbitrary files via a symlink attack.
Screen savers in KDE beta 3 allows local users to overwrite arbitrary files via a symlink attack on the .kss.pid file.
KDE kppp allows local users to create a directory in an arbitrary location via the HOME environmental variable.