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.

plugin/npapi/plugin.cpp in Gnash before 0.8.10 uses weak permissions (world readable) for cookie files with predictable names in /tmp, which allows local users to obtain sensitive information.

Integer overflow in the GnashImage::size method in libbase/GnashImage.h in GNU Gnash 0.8.10 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted SWF file, which triggers a heap-based buffer overflow.