PostgreSQL 11.3, 10.8, 9.6.13, 9.5.17, and 9.4.22 Released!

2019-05-09 Cumulative Security Update
=====================================

The PostgreSQL Global Development Group has released an update to all
supported versions of our database system, including 11.3, 10.8, 9.6.13,
9.5.17, and 9.4.22. This release fixes two security issues in the
PostgreSQL server, a security issue found in two of the PostgreSQL
Windows installers, and over 60 bugs reported over the last three months.

Users who installed PostgreSQL using the Windows installers from
EnterpriseDB and BigSQL respectively should upgrade as soon as possible.
Similarly, users who are running any version of PostgreSQL 9.5, 9.6, 10,
and 11 should also plan to upgrade as soon as possible.

All other users should plan to apply this update at the next scheduled
downtime.

Security Issues
---------------

Four security vulnerabilities have been closed by this release:

* CVE-2019-10127: BigSQL Windows installer does not clear permissive ACL
entries
* CVE-2019-10128: EnterpriseDB Windows installer does not clear
permissive ACL entries

Due to both the EnterpriseDB and BigSQL Windows installers not locking
down the permissions of the PostgreSQL binary installation directory and
the data directory, an unprivileged Windows user account and an
unprivileged PostgreSQL account could cause the PostgreSQL service
account to execute arbitrary code.

This vulnerability is present in all supported versions of PostgreSQL
for these installers, and possibly exists in older versions. Both sets
of installers have fixed the permissions for these directories for both
new and existing installations. If you have installed PostgreSQL on
Windows using other methods, we advise that you check that your
PostgreSQL binary directories are writable only to trusted users and
that your data directories are only accessible to trusted users.

The PostgreSQL project thanks Conner Jones for reporting this problem.

* CVE-2019-10129: Memory disclosure in partition routing

Prior to this release, a user running PostgreSQL 11 can read arbitrary
bytes of server memory by executing a purpose-crafted INSERT statement
to a partitioned table.

* CVE-2019-10130: Selectivity estimators bypass row security policies

PostgreSQL maintains statistics for tables by sampling data available in
columns; this data is consulted during the query planning process. Prior
to this release, a user able to execute SQL queries with permissions to
read a given column could craft a leaky operator that could read
whatever data had been sampled from that column. If this happened to
include values from rows that the user is forbidden to see by a row
security policy, the user could effectively bypass the policy. This is
fixed by only allowing a non-leakproof operator to use this data if
there are no relevant row security policies for the table.

This issue is present in PostgreSQL 9.5, 9.6, 10, and 11. The PostgreSQL
project thanks Dean Rasheed for reporting this problem.

Bug Fixes and Improvements
--------------------------

This update also fixes over 60 bugs that were reported in the last
several months. Some of these issues affect only version 11, but many
affect all supported versions.

Some of these fixes include:

* Several catalog corruption fixes, including one related to running
`ALTER TABLE` on a partitioned table
* Several fixes for partitioning
* Avoid server crash when an error occurs while trying to persist a
cursor query across a transaction commit
* Avoid O(N^2) performance issue when rolling back a transaction that
created many tables
* Fix possible “could not access status of transaction” failures in
`txid_status()`
* Fix updatable views to handle explicit DEFAULT items in `INSERT ..
VALUES` statements where there are multiple VALUES rows
* Fix CREATE VIEW to allow zero-column views
* Add missing support for the `CREATE TABLE IF NOT EXISTS .. AS EXECUTE
..` statement
* Ensure that sub-SELECTs appearing in row-level-security policy
expressions are executed with the correct user's permissions
* Accept XML documents as valid values of type xml when xmloption is set
to content, as required by SQL:2006 and later
* Fix incompatibility of GIN-index WAL records that were introduced in
11.2, 10.7, 9.6.12, 9.5.16, and 9.4.21 that affected replica servers
running these versions reading in changes to GIN indexes from primary
servers of older versions
* Several memory leak fixes as well as fixes to management of dynamic
shared memory
* Relax panics on fsync and sync_file_range failures for certain cases
where a failure indicated "operation not supported"
* Several fixes to the query planner, several of which should lead to
planning improvements
* Fix race condition in which a hot-standby postmaster could fail to
shut down after receiving a smart-shutdown request
* Several fixes for SCRAM authentication
* Fix handling of `lc_time` settings that imply an encoding different
from the database's encoding
* Create the `current_logfiles` file with the same permissions as other
files in the server's `data` directory
* Several ecpg fixes
* Make `pg_verify_checksums` verify that the data directory it's pointed
at is of the right PostgreSQL version
* Several fixes for `contrib/postgres_fdw`, including one for remote
partitions where an UPDATE could lead to incorrect results or a crash
* Several Windows fixes

This update also contains tzdata release 2019a for DST law changes in
Palestine and Metlakatla, plus historical corrections for Israel.
Etc/UCT is now a backward-compatibility link to Etc/UTC, instead of
being a separate zone that generates the abbreviation UCT, which
nowadays is typically a typo. PostgreSQL will still accept UCT as an
input zone abbreviation, but it won't output it.

Updating
--------

All PostgreSQL update releases are cumulative. As with other minor
releases, users are not required to dump and reload their database or
use `pg_upgrade` in order to apply this update release; you may simply
shutdown PostgreSQL and update its binaries.

Users who have skipped one or more update releases may need to run
additional, post-update steps; please see the release notes for earlier
versions for details.

PostgreSQL 9.4 will stop receiving fixes on February 13, 2020. Please
see our versioning policy for more information.

Links
-----
* Download: https://www.postgresql.org/download/
* Release Notes: https://www.postgresql.org/docs/11/release.html
* Security Page: https://www.postgresql.org/support/security/
* Versioning Policy: https://www.postgresql.org/support/versioning/
* Follow @postgresql on Twitter: https://twitter.com/postgresql