In Phusion Passenger before 5.1.0, a known /tmp filename was used during passenger-install-nginx-module execution, which could allow local attackers to gain the privileges of the passenger user.
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:HI:HA:H7.8/CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H