User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:23.0) Gecko/20100101 Firefox/23.0 (Beta/Release) Build ID: 20130814063812 Steps to reproduce: I've made a function in javascript for a tool that I will use it in my test And I did an mistake in that function that made my code to loop at infinite. Actual results: Because I use event attribute onkeyup the message "Stop this Script" refuse to appear. When I used same script but I changed the attribute to onmouseover, the message "Stop this script" appeared. Expected results: I don't think to explain the expected result. So, the function I written was: ########################################## function checkOctal(ip) { var d = ip.split('.'); var ip1 = parseInt(d[0]).toString(8); var ip2 = parseInt(d[1]).toString(8); var ip3 = parseInt(d[2]).toString(8); var ip4 = parseInt(d[3]).toString(8); while(ip1.length != 3){ ip1 = "0"+ ip1; } while(ip2.length != 3){ ip2 = "0"+ ip1; } while(ip3.length != 3){ ip3 = "0"+ ip1; } while(ip4.length != 3){ ip4 = "0"+ ip1; } return ("http://"+ip1+ip2+ip3+ip4+"/"); } ########################################## you have the html file at attachments for a P.o.C.

flagging bug as a security bug

I don't understand, this is a security problem or not?

Cernica, This is considered a very minor security issue as a denial of service attack.

This issue appears to be fixed in Firefox 59.