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.

PostgreSQL versions before 9.2.22, 9.3.18, 9.4.13, 9.5.8 and 9.6.4 are vulnerable to authorization flaw allowing remote authenticated attackers to retrieve passwords from the user mappings defined by the foreign server owners without actually having the privileges to do so.

PostgreSQL versions before 9.2.22, 9.3.18, 9.4.13, 9.5.8 and 9.6.4 are vulnerable to incorrect authentication flaw allowing remote attackers to gain access to database accounts with an empty password.

PostgreSQL versions 8.4 - 9.6 are vulnerable to information leak in pg_user_mappings view which discloses foreign server passwords to any user having USAGE privilege on the associated foreign server.

PostgreSQL before 9.1.23, 9.2.x before 9.2.18, 9.3.x before 9.3.14, 9.4.x before 9.4.9, and 9.5.x before 9.5.4 might allow remote authenticated users with the CREATEDB or CREATEROLE role to gain superuser privileges via a (1) " (double quote), (2) \ (backslash), (3) carriage return, or (4) newline character in a (a) database or (b) role name that is mishandled during an administrative operation.

PostgreSQL before 9.1.23, 9.2.x before 9.2.18, 9.3.x before 9.3.14, 9.4.x before 9.4.9, and 9.5.x before 9.5.4 allow remote authenticated users to cause a denial of service (NULL pointer dereference and server crash), obtain sensitive memory information, or possibly execute arbitrary code via (1) a CASE expression within the test value subexpression of another CASE or (2) inlining of an SQL function that implements the equality operator used for a CASE expression involving values of different types.

PostgreSQL before 9.1.20, 9.2.x before 9.2.15, 9.3.x before 9.3.11, 9.4.x before 9.4.6, and 9.5.x before 9.5.1 allows remote attackers to cause a denial of service (infinite loop or buffer overflow and crash) via a large Unicode character range in a regular expression.

The crypt function in contrib/pgcrypto in PostgreSQL before 9.0.23, 9.1.x before 9.1.19, 9.2.x before 9.2.14, 9.3.x before 9.3.10, and 9.4.x before 9.4.5 allows attackers to cause a denial of service (server crash) or read arbitrary server memory via a "too-short" salt.

Double free vulnerability in PostgreSQL before 9.0.20, 9.1.x before 9.1.16, 9.2.x before 9.2.11, 9.3.x before 9.3.7, and 9.4.x before 9.4.2 allows remote attackers to cause a denial of service (crash) by closing an SSL session at a time when the authentication timeout will expire during the session shutdown sequence.

The "make check" command for the test suites in PostgreSQL 9.3.3 and earlier does not properly invoke initdb to specify the authentication requirements for a database cluster to be used for the tests, which allows local users to gain privileges by leveraging access to this cluster.