The configure script in gnash 0.8.8 allows local users to overwrite arbitrary files via a symlink attack on the (1) /tmp/gnash-configure-errors.$$, (2) /tmp/gnash-configure-warnings.$$, or (3) /tmp/gnash-configure-recommended.$$ files.
http://www.securityfocus.com/bid/45102
http://www.debian.org/security/2012/dsa-2435
http://secunia.com/advisories/48466