Came across this on the forums (https://forums.gentoo.org/viewtopic-t-556469.html), there's some DoS using animated gifs. http://www.securityfocus.com/bid/22899/info says it affects 220.127.116.11, but my 18.104.22.168 just crashed too.
Steps to Reproduce:
Thx for the report. However we don't usually treat one time client crashes as security issues. Reassigning to mozilla.
This should be fixed upstream