postgres

Author SHA1 Message Date

Author	SHA1	Message	Date
Tom Lane	7eeb1d9861	Make contrib modules' installation scripts more secure. Hostile objects located within the installation-time search_path could capture references in an extension's installation or upgrade script. If the extension is being installed with superuser privileges, this opens the door to privilege escalation. While such hazards have existed all along, their urgency increases with the v13 "trusted extensions" feature, because that lets a non-superuser control the installation path for a superuser-privileged script. Therefore, make a number of changes to make such situations more secure: * Tweak the construction of the installation-time search_path to ensure that references to objects in pg_catalog can't be subverted; and explicitly add pg_temp to the end of the path to prevent attacks using temporary objects. * Disable check_function_bodies within installation/upgrade scripts, so that any security gaps in SQL-language or PL-language function bodies cannot create a risk of unwanted installation-time code execution. * Adjust lookup of type input/receive functions and join estimator functions to complain if there are multiple candidate functions. This prevents capture of references to functions whose signature is not the first one checked; and it's arguably more user-friendly anyway. * Modify various contrib upgrade scripts to ensure that catalog modification queries are executed with secure search paths. (These are in-place modifications with no extension version changes, since it is the update process itself that is at issue, not the end result.) Extensions that depend on other extensions cannot be made fully secure by these methods alone; therefore, revert the "trusted" marking that commit `eb67623c9` applied to earthdistance and hstore_plperl, pending some better solution to that set of issues. Also add documentation around these issues, to help extension authors write secure installation scripts. Patch by me, following an observation by Andres Freund; thanks to Noah Misch for review. Security: CVE-2020-14350	5 years ago
Tom Lane	eb67623c96	Mark some contrib modules as "trusted". This allows these modules to be installed into a database without superuser privileges (assuming that the DBA or sysadmin has installed the module's files in the expected place). You only need CREATE privilege on the current database, which by default would be available to the database owner. The following modules are marked trusted: btree_gin btree_gist citext cube dict_int earthdistance fuzzystrmatch hstore hstore_plperl intarray isn jsonb_plperl lo ltree pg_trgm pgcrypto seg tablefunc tcn tsm_system_rows tsm_system_time unaccent uuid-ossp In the future we might mark some more modules trusted, but there seems to be no debate about these, and on the whole it seems wise to be conservative with use of this feature to start out with. Discussion: https://postgr.es/m/32315.1580326876@sss.pgh.pa.us	6 years ago
Peter Eisentraut	cac7658205	Add transforms feature This provides a mechanism for specifying conversions between SQL data types and procedural languages. As examples, there are transforms for hstore and ltree for PL/Perl and PL/Python. reviews by Pavel Stěhule and Andres Freund	11 years ago

Tom Lane

Make contrib modules' installation scripts more secure.

Hostile objects located within the installation-time search_path could
capture references in an extension's installation or upgrade script.
If the extension is being installed with superuser privileges, this
opens the door to privilege escalation.  While such hazards have existed
all along, their urgency increases with the v13 "trusted extensions"
feature, because that lets a non-superuser control the installation path
for a superuser-privileged script.  Therefore, make a number of changes
to make such situations more secure:

* Tweak the construction of the installation-time search_path to ensure
that references to objects in pg_catalog can't be subverted; and
explicitly add pg_temp to the end of the path to prevent attacks using
temporary objects.

* Disable check_function_bodies within installation/upgrade scripts,
so that any security gaps in SQL-language or PL-language function bodies
cannot create a risk of unwanted installation-time code execution.

* Adjust lookup of type input/receive functions and join estimator
functions to complain if there are multiple candidate functions.  This
prevents capture of references to functions whose signature is not the
first one checked; and it's arguably more user-friendly anyway.

* Modify various contrib upgrade scripts to ensure that catalog
modification queries are executed with secure search paths.  (These
are in-place modifications with no extension version changes, since
it is the update process itself that is at issue, not the end result.)

Extensions that depend on other extensions cannot be made fully secure
by these methods alone; therefore, revert the "trusted" marking that
commit eb67623c9 applied to earthdistance and hstore_plperl, pending
some better solution to that set of issues.

Also add documentation around these issues, to help extension authors
write secure installation scripts.

Patch by me, following an observation by Andres Freund; thanks
to Noah Misch for review.

Security: CVE-2020-14350

5 years ago

Tom Lane

eb67623c96

Mark some contrib modules as "trusted".

This allows these modules to be installed into a database without
superuser privileges (assuming that the DBA or sysadmin has installed
the module's files in the expected place).  You only need CREATE
privilege on the current database, which by default would be
available to the database owner.

The following modules are marked trusted:

btree_gin
btree_gist
citext
cube
dict_int
earthdistance
fuzzystrmatch
hstore
hstore_plperl
intarray
isn
jsonb_plperl
lo
ltree
pg_trgm
pgcrypto
seg
tablefunc
tcn
tsm_system_rows
tsm_system_time
unaccent
uuid-ossp

In the future we might mark some more modules trusted, but there
seems to be no debate about these, and on the whole it seems wise
to be conservative with use of this feature to start out with.

Discussion: https://postgr.es/m/32315.1580326876@sss.pgh.pa.us

6 years ago

Peter Eisentraut

cac7658205

Add transforms feature

This provides a mechanism for specifying conversions between SQL data
types and procedural languages.  As examples, there are transforms
for hstore and ltree for PL/Perl and PL/Python.

reviews by Pavel Stěhule and Andres Freund

11 years ago

3 Commits (cb36f8ec2124b0c495da057a2f55735fe858be0e)