Tom Ferris discovered a bug in the IDN hostname handling of Mozilla
Firefox, which is also present in the other browsers from the same
family that allows remote attackers to cause a denial of service and
possibly execute arbitrary code via a hostname with dashes.
For the stable distribution (sarge) this problem has been fixed in
version 1.0.4-2sarge4.
For the unstable distribution (sid) this problem has been fixed in
version 1.0.6-5.
We recommend that you upgrade your mozilla-firefox package.