issetugid() + rsh + libmalloc OS X Local Root Exploit

The default root-suid binary /usr/bin/rsh on Mac OS X uses execv in an insecure manner. /usr/bin/rsh will invoke /usr/bin/rlogin if launched with only a host argument, without dropping privileges or clearing the environment. This exploit will pass "MallocLogFile" to /usr/bin/rsh, which is then...