Phusion Passenger gem before 3.0.21 and 4.0.x before 4.0.5 for Ruby allows local users to cause a denial of service (prevent application start) or gain privileges by pre-creating a temporary "config" file in a directory with a predictable name in /tmp/ before it is used by the gem.
Exploitability
AV:LAC:LAu:NImpact
C:PI:PA:P4.6/AV:L/AC:L/Au:N/C:P/I:P/A:P