PostgreSQL Improper Link Resolution Before File Access (Link Following) Vulnerability - CVE-2017-12172

PostgreSQL 10.x before 10.1 9.6.x before 9.6.6 9.5.x before 9.5.10 9.4.x before 9.4.15 9.3.x before 9.3.20 and 9.2.x before 9.2.24 runs under a non-root operating system account and database superusers have effective ability to run arbitrary code under that system account. PostgreSQL provides a script for starting the database server during system boot. Packages of PostgreSQL for many operating systems provide their own packager-authored startup implementations. Several implementations use a log file name that the database superuser can replace with a symbolic link. As root they open() chmod() and/or chown() this log file name. This often suffices for the database superuser to escalate to root privileges when root starts the server.