From b5b124046c0dc636d73c4a802bc731431dfd9dba Mon Sep 17 00:00:00 2001 From: Noah Misch Date: Mon, 8 May 2017 07:24:24 -0700 Subject: [PATCH] Match pg_user_mappings limits to information_schema.user_mapping_options. Both views replace the umoptions field with NULL when the user does not meet qualifications to see it. They used different qualifications, and pg_user_mappings documented qualifications did not match its implemented qualifications. Make its documentation and implementation match those of user_mapping_options. One might argue for stronger qualifications, but these have long, documented tenure. pg_user_mappings has always exhibited this problem, so back-patch to 9.2 (all supported versions). Michael Paquier and Feike Steenbergen. Reviewed by Jeff Janes. Reported by Andrew Wheelwright. Security: CVE-2017-7486 --- doc/src/sgml/catalogs.sgml | 7 ++- src/backend/catalog/system_views.sql | 10 ++-- src/test/regress/expected/foreign_data.out | 54 ++++++++++++++++++++++ src/test/regress/expected/rules.out | 4 +- src/test/regress/sql/foreign_data.sql | 15 ++++++ 5 files changed, 82 insertions(+), 8 deletions(-) diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml index 518d2fa4b50..52de61c3956 100644 --- a/doc/src/sgml/catalogs.sgml +++ b/doc/src/sgml/catalogs.sgml @@ -9212,8 +9212,11 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx User mapping specific options, as keyword=value - strings, if the current user is the owner of the foreign - server, else null + strings. This column will show as null unless the current user + is the user being mapped, or the mapping is for + PUBLIC and the current user is the server + owner, or the current user is a superuser. The intent is + to protect password information stored as user mapping option. diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index 81d7c4fec8c..699283b1328 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -696,11 +696,11 @@ CREATE VIEW pg_user_mappings AS ELSE A.rolname END AS usename, - CASE WHEN pg_has_role(S.srvowner, 'USAGE') OR has_server_privilege(S.oid, 'USAGE') THEN - U.umoptions - ELSE - NULL - END AS umoptions + CASE WHEN (U.umuser <> 0 AND A.rolname = current_user) + OR (U.umuser = 0 AND pg_has_role(S.srvowner, 'USAGE')) + OR (SELECT rolsuper FROM pg_authid WHERE rolname = current_user) + THEN U.umoptions + ELSE NULL END AS umoptions FROM pg_user_mapping U LEFT JOIN pg_authid A ON (A.oid = U.umuser) JOIN pg_foreign_server S ON (U.umserver = S.oid); diff --git a/src/test/regress/expected/foreign_data.out b/src/test/regress/expected/foreign_data.out index 857f1cefb2d..ebbe54989eb 100644 --- a/src/test/regress/expected/foreign_data.out +++ b/src/test/regress/expected/foreign_data.out @@ -1157,7 +1157,61 @@ WARNING: no privileges were granted for "s9" CREATE USER MAPPING FOR current_user SERVER s9; DROP SERVER s9 CASCADE; -- ERROR ERROR: must be owner of foreign server s9 +-- Check visibility of user mapping data +SET ROLE regress_test_role; +CREATE SERVER s10 FOREIGN DATA WRAPPER foo; +CREATE USER MAPPING FOR public SERVER s10 OPTIONS (user 'secret'); +GRANT USAGE ON FOREIGN SERVER s10 TO unprivileged_role; +-- owner of server can see option fields +\deu+ + List of user mappings + Server | User name | FDW Options +--------+-------------------+------------------- + s10 | public | ("user" 'secret') + s4 | foreign_data_user | + s5 | regress_test_role | (modified '1') + s6 | regress_test_role | + s8 | foreign_data_user | + s8 | public | + s9 | unprivileged_role | + t1 | public | (modified '1') +(8 rows) + RESET ROLE; +-- superuser can see option fields +\deu+ + List of user mappings + Server | User name | FDW Options +--------+-------------------+--------------------- + s10 | public | ("user" 'secret') + s4 | foreign_data_user | + s5 | regress_test_role | (modified '1') + s6 | regress_test_role | + s8 | foreign_data_user | (password 'public') + s8 | public | + s9 | unprivileged_role | + t1 | public | (modified '1') +(8 rows) + +-- unprivileged user cannot see option fields +SET ROLE unprivileged_role; +\deu+ + List of user mappings + Server | User name | FDW Options +--------+-------------------+------------- + s10 | public | + s4 | foreign_data_user | + s5 | regress_test_role | + s6 | regress_test_role | + s8 | foreign_data_user | + s8 | public | + s9 | unprivileged_role | + t1 | public | +(8 rows) + +RESET ROLE; +DROP SERVER s10 CASCADE; +NOTICE: drop cascades to user mapping for public on server s10 -- DROP FOREIGN TABLE DROP FOREIGN TABLE no_table; -- ERROR ERROR: foreign table "no_table" does not exist diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 864e69be546..773b60d1d58 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -2026,7 +2026,9 @@ SELECT viewname, definition FROM pg_views WHERE schemaname <> 'information_schem | ELSE a.rolname + | END AS usename, + | CASE + - | WHEN (pg_has_role(s.srvowner, 'USAGE'::text) OR has_server_privilege(s.oid, 'USAGE'::text)) THEN u.umoptions + + | WHEN ((((u.umuser <> (0)::oid) AND (a.rolname = "current_user"())) OR ((u.umuser = (0)::oid) AND pg_has_role(s.srvowner, 'USAGE'::text))) OR ( SELECT pg_authid.rolsuper + + | FROM pg_authid + + | WHERE (pg_authid.rolname = "current_user"()))) THEN u.umoptions + | ELSE NULL::text[] + | END AS umoptions + | FROM ((pg_user_mapping u + diff --git a/src/test/regress/sql/foreign_data.sql b/src/test/regress/sql/foreign_data.sql index 3dcbf0fbbc7..bf69cdfbc90 100644 --- a/src/test/regress/sql/foreign_data.sql +++ b/src/test/regress/sql/foreign_data.sql @@ -468,7 +468,22 @@ ALTER SERVER s9 VERSION '1.2'; -- ERROR GRANT USAGE ON FOREIGN SERVER s9 TO regress_test_role; -- WARNING CREATE USER MAPPING FOR current_user SERVER s9; DROP SERVER s9 CASCADE; -- ERROR + +-- Check visibility of user mapping data +SET ROLE regress_test_role; +CREATE SERVER s10 FOREIGN DATA WRAPPER foo; +CREATE USER MAPPING FOR public SERVER s10 OPTIONS (user 'secret'); +GRANT USAGE ON FOREIGN SERVER s10 TO unprivileged_role; +-- owner of server can see option fields +\deu+ RESET ROLE; +-- superuser can see option fields +\deu+ +-- unprivileged user cannot see option fields +SET ROLE unprivileged_role; +\deu+ +RESET ROLE; +DROP SERVER s10 CASCADE; -- DROP FOREIGN TABLE DROP FOREIGN TABLE no_table; -- ERROR