Unspecified vulnerability in Opera before 9.52 on Windows, when registered as a protocol handler, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via unknown vectors in which Opera is launched by other applications.
https://exchange.xforce.ibmcloud.com/vulnerabilities/44547
http://www.vupen.com/english/advisories/2008/2416
http://www.securityfocus.com/bid/30768
http://www.opera.com/support/search/view/892/