Buffer overflow in Opera 6.05 and 6.06, and possibly other versions, allows remote attackers to execute arbitrary code via a URL with a long username.
https://exchange.xforce.ibmcloud.com/vulnerabilities/11281
https://euvd.enisa.europa.eu/vulnerability/EUVD-2003-1377
http://www.securityfocus.com/bid/6811
http://www.securityfocus.com/archive/1/315794