The (1) gendef.sh, (2) doc/fixinfo.sh, and (3) contrib/gdiffmk/tests/runtests.in scripts in GNU troff (aka groff) 1.21 and earlier allow local users to overwrite arbitrary files via a symlink attack on a gro#####.tmp or /tmp/##### temporary file.
cvsweb.openwall.com/cgi/cvsweb.cgi/Owl/packages/groff/groff-1.20.1-owl-tmp.diff
cvsweb.openwall.com/cgi/cvsweb.cgi/Owl/packages/groff/groff-1.20.1-owl-tmp.diff.diff?r1=1.1;r2=1.2;f=h
openwall.com/lists/oss-security/2009/08/14/4
openwall.com/lists/oss-security/2009/08/14/5
www.mandriva.com/security/advisories?name=MDVSA-2013:085
www.mandriva.com/security/advisories?name=MDVSA-2013:086