postgresql/contrib
Tom Lane 6b11a46878 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
2020-08-10 10:44:43 -04:00
..
adminpack Add missing errcode() in a few ereport calls. 2020-03-18 10:10:27 +05:30
auth_delay
auto_explain
btree_gin
btree_gist Get rid of trailing semicolons in C macro definitions. 2020-05-01 17:28:01 -04:00
chkpass
citext Make contrib modules' installation scripts more secure. 2020-08-10 10:44:43 -04:00
cube
dblink Initialize dblink remoteConn struct in all cases 2020-05-28 13:45:15 -04:00
dict_int
dict_xsyn
earthdistance Make contrib modules' installation scripts more secure. 2020-08-10 10:44:43 -04:00
file_fdw
fuzzystrmatch
hstore Make contrib modules' installation scripts more secure. 2020-08-10 10:44:43 -04:00
hstore_plperl
hstore_plpython
intagg
intarray Make contrib modules' installation scripts more secure. 2020-08-10 10:44:43 -04:00
isn
lo Fix bogus CALLED_AS_TRIGGER() defenses. 2020-04-03 11:24:56 -04:00
ltree Back-patch addition of stack overflow and interrupt checks for lquery. 2020-03-31 11:37:44 -04:00
ltree_plpython
oid2name
pageinspect
passwordcheck
pg_buffercache
pg_freespacemap
pg_prewarm
pg_standby
pg_stat_statements
pg_trgm Make contrib modules' installation scripts more secure. 2020-08-10 10:44:43 -04:00
pgcrypto Fix corner case with 16kB-long decompression in pgcrypto, take 2 2020-07-27 15:59:22 +09:00
pgrowlocks Avoid holding a directory FD open across assorted SRF calls. 2020-03-16 21:05:29 -04:00
pgstattuple
postgres_fdw
seg
sepgsql Fix cache reference leak in contrib/sepgsql. 2020-04-16 14:45:54 -04:00
spi
sslinfo
start-scripts
tablefunc
tcn
test_decoding
tsearch2 Make contrib modules' installation scripts more secure. 2020-08-10 10:44:43 -04:00
tsm_system_rows
tsm_system_time
unaccent
uuid-ossp
vacuumlo
xml2
contrib-global.mk
Makefile
README

The PostgreSQL contrib tree
---------------------------

This subtree contains porting tools, analysis utilities, and plug-in
features that are not part of the core PostgreSQL system, mainly
because they address a limited audience or are too experimental to be
part of the main source tree.  This does not preclude their
usefulness.

User documentation for each module appears in the main SGML
documentation.

When building from the source distribution, these modules are not
built automatically, unless you build the "world" target.  You can
also build and install them all by running "make all" and "make
install" in this directory; or to build and install just one selected
module, do the same in that module's subdirectory.

Some directories supply new user-defined functions, operators, or
types.  To make use of one of these modules, after you have installed
the code you need to register the new SQL objects in the database
system by executing a CREATE EXTENSION command.  In a fresh database,
you can simply do

    CREATE EXTENSION module_name;

See the PostgreSQL documentation for more information about this
procedure.