Unspecified vulnerability in stunnel before 4.23, when running as a service on Windows, allows local users to gain privileges via unknown attack vectors.
https://exchange.xforce.ibmcloud.com/vulnerabilities/42526
http://www.vupen.com/english/advisories/2008/1568/references
http://www.securitytracker.com/id?1020049
http://www.securityfocus.com/bid/29285
http://stunnel.mirt.net/pipermail/stunnel-announce/2008-May/000034.html