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mirror of https://github.com/postgres/postgres.git synced 2025-07-27 12:41:57 +03:00

Replace last PushOverrideSearchPath() call with set_config_option().

The two methods don't cooperate, so set_config_option("search_path",
...) has been ineffective under non-empty overrideStack.  This defect
enabled an attacker having database-level CREATE privilege to execute
arbitrary code as the bootstrap superuser.  While that particular attack
requires v13+ for the trusted extension attribute, other attacks are
feasible in all supported versions.

Standardize on the combination of NewGUCNestLevel() and
set_config_option("search_path", ...).  It is newer than
PushOverrideSearchPath(), more-prevalent, and has no known
disadvantages.  The "override" mechanism remains for now, for
compatibility with out-of-tree code.  Users should update such code,
which likely suffers from the same sort of vulnerability closed here.
Back-patch to v11 (all supported versions).

Alexander Lakhin.  Reported by Alexander Lakhin.

Security: CVE-2023-2454
This commit is contained in:
Noah Misch
2023-05-08 06:14:07 -07:00
parent 8229bfe91d
commit dbd5795e75
7 changed files with 165 additions and 11 deletions

View File

@ -13,7 +13,7 @@ PGFILEDESC = "seg - line segment data type"
HEADERS = segdata.h
REGRESS = seg
REGRESS = security seg
EXTRA_CLEAN = y.tab.c y.tab.h

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@ -0,0 +1,32 @@
--
-- Test extension script protection against search path overriding
--
CREATE ROLE regress_seg_role;
SELECT current_database() AS datname \gset
GRANT CREATE ON DATABASE :"datname" TO regress_seg_role;
SET ROLE regress_seg_role;
CREATE SCHEMA regress_seg_schema;
CREATE FUNCTION regress_seg_schema.exfun(i int) RETURNS int AS $$
BEGIN
CREATE EXTENSION seg VERSION '1.2';
CREATE FUNCTION regress_seg_schema.compare(oid, regclass) RETURNS boolean AS
'BEGIN RAISE EXCEPTION ''overloaded compare() called by %'', current_user; END;' LANGUAGE plpgsql;
CREATE OPERATOR = (LEFTARG = oid, RIGHTARG = regclass, PROCEDURE = regress_seg_schema.compare);
ALTER EXTENSION seg UPDATE TO '1.3';
RETURN i;
END; $$ LANGUAGE plpgsql;
CREATE SCHEMA test_schema
CREATE TABLE t(i int) PARTITION BY RANGE (i)
CREATE TABLE p1 PARTITION OF t FOR VALUES FROM (1) TO (regress_seg_schema.exfun(2));
DROP SCHEMA test_schema CASCADE;
NOTICE: drop cascades to 3 other objects
DETAIL: drop cascades to table test_schema.t
drop cascades to extension seg
drop cascades to operator test_schema.=(oid,regclass)
RESET ROLE;
DROP OWNED BY regress_seg_role;
DROP ROLE regress_seg_role;

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@ -0,0 +1,32 @@
--
-- Test extension script protection against search path overriding
--
CREATE ROLE regress_seg_role;
SELECT current_database() AS datname \gset
GRANT CREATE ON DATABASE :"datname" TO regress_seg_role;
SET ROLE regress_seg_role;
CREATE SCHEMA regress_seg_schema;
CREATE FUNCTION regress_seg_schema.exfun(i int) RETURNS int AS $$
BEGIN
CREATE EXTENSION seg VERSION '1.2';
CREATE FUNCTION regress_seg_schema.compare(oid, regclass) RETURNS boolean AS
'BEGIN RAISE EXCEPTION ''overloaded compare() called by %'', current_user; END;' LANGUAGE plpgsql;
CREATE OPERATOR = (LEFTARG = oid, RIGHTARG = regclass, PROCEDURE = regress_seg_schema.compare);
ALTER EXTENSION seg UPDATE TO '1.3';
RETURN i;
END; $$ LANGUAGE plpgsql;
CREATE SCHEMA test_schema
CREATE TABLE t(i int) PARTITION BY RANGE (i)
CREATE TABLE p1 PARTITION OF t FOR VALUES FROM (1) TO (regress_seg_schema.exfun(2));
DROP SCHEMA test_schema CASCADE;
RESET ROLE;
DROP OWNED BY regress_seg_role;
DROP ROLE regress_seg_role;