BSD setusercontext Vulnerabilities

BSD setusercontext vulnerabilites discovered by Kingcope, July 2009 lewls XD Let's go.. BSD derived operating systems have a special function to set a "user context". The function setusercontext is available on for example FreeBSD 5.0 and 7.0. An example from ftpd.c : setusercontextlc, pw, uidt0,...