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Tom Lane e3b01bc1e1 Prevent indirect security attacks via changing session-local state within
an allegedly immutable index function.  It was previously recognized that
we had to prevent such a function from executing SET/RESET ROLE/SESSION
AUTHORIZATION, or it could trivially obtain the privileges of the session
user.  However, since there is in general no privilege checking for changes
of session-local state, it is also possible for such a function to change
settings in a way that might subvert later operations in the same session.
Examples include changing search_path to cause an unexpected function to
be called, or replacing an existing prepared statement with another one
that will execute a function of the attacker's choosing.

The present patch secures VACUUM, ANALYZE, and CREATE INDEX/REINDEX against
these threats, which are the same places previously deemed to need protection
against the SET ROLE issue.  GUC changes are still allowed, since there are
many useful cases for that, but we prevent security problems by forcing a
rollback of any GUC change after completing the operation.  Other cases are
handled by throwing an error if any change is attempted; these include temp
table creation, closing a cursor, and creating or deleting a prepared
statement.  (In 7.4, the infrastructure to roll back GUC changes doesn't
exist, so we settle for rejecting changes of "search_path" in these contexts.)

Original report and patch by Gurjeet Singh, additional analysis by
Tom Lane.

Security: CVE-2009-4136
2009-12-09 21:58:17 +00:00
config Detect and error out on inability to get proper linkage information required for plperl, usually due to absence of perl ExtUtils::Embed module. Backpatch as far as 8.1. 2008-11-12 00:00:29 +00:00
contrib Disable triggering failover with a signal in pg_standby on Windows, because 2009-11-04 12:51:42 +00:00
doc Fix syntax in extract() examples 2009-11-24 19:20:53 +00:00
src Prevent indirect security attacks via changing session-local state within 2009-12-09 21:58:17 +00:00
aclocal.m4 Add new auto-detection of thread flags. 2004-04-23 18:15:55 +00:00
configure Tag 8.3.8 2009-09-04 00:53:29 +00:00
configure.in Tag 8.3.8 2009-09-04 00:53:29 +00:00
COPYRIGHT Update copyrights in source tree to 2008. 2008-01-01 19:46:01 +00:00
GNUmakefile.in Replace useless uses of := by = in makefiles. 2007-02-09 15:56:00 +00:00
Makefile Remove remains of old depend target. 2007-01-20 17:16:17 +00:00
README Update libpqxx URL in top-level README, per Gurjeet Singh. 2008-03-05 17:04:42 +00:00
README.CVS Some further editorializing on README.CVS. 2004-03-28 06:09:08 +00:00

PostgreSQL Database Management System
=====================================
  
This directory contains the source code distribution of the PostgreSQL
database management system.

PostgreSQL is an advanced object-relational database management system
that supports an extended subset of the SQL standard, including
transactions, foreign keys, subqueries, triggers, user-defined types
and functions.  This distribution also contains C language bindings.

PostgreSQL has many language interfaces including some of the more
common listed below:

C++ - http://pqxx.org/development/libpqxx/
JDBC - http://jdbc.postgresql.org
ODBC - http://odbc.postgresql.org
Perl - http://search.cpan.org/~dbdpg/
PHP - http://www.php.net
Python - http://www.initd.org/
Ruby - http://ruby.scripting.ca/postgres/

Other language binding are available from a variety of contributing
parties.

PostgreSQL also has a great number of procedural languages available,
a short, incomplete list is below:

PL/pgSQL - included in PostgreSQL source distribution
PL/Perl - included in PostgreSQL source distribution
PL/PHP - http://projects.commandprompt.com/projects/public/plphp
PL/Python - included in PostgreSQL source distribution
PL/Java - http://pgfoundry.org/projects/pljava/
PL/Tcl - included in PostgreSQL source distribution

See the file INSTALL for instructions on how to build and install
PostgreSQL.  That file also lists supported operating systems and
hardware platforms and contains information regarding any other
software packages that are required to build or run the PostgreSQL
system.  Changes between all PostgreSQL releases are recorded in the
file HISTORY.  Copyright and license information can be found in the
file COPYRIGHT.  A comprehensive documentation set is included in this
distribution; it can be read as described in the installation
instructions.

The latest version of this software may be obtained at
http://www.postgresql.org/download/.  For more information look at our
web site located at http://www.postgresql.org/.