582edc369c
This makes the client programs behave as documented regardless of the connect-time search_path and regardless of user-created objects. Today, a malicious user with CREATE permission on a search_path schema can take control of certain of these clients' queries and invoke arbitrary SQL functions under the client identity, often a superuser. This is exploitable in the default configuration, where all users have CREATE privilege on schema "public". This changes behavior of user-defined code stored in the database, like pg_index.indexprs and pg_extension_config_dump(). If they reach code bearing unqualified names, "does not exist" or "no schema has been selected to create in" errors might appear. Users may fix such errors by schema-qualifying affected names. After upgrading, consider watching server logs for these errors. The --table arguments of src/bin/scripts clients have been lax; for example, "vacuumdb -Zt pg_am\;CHECKPOINT" performed a checkpoint. That now fails, but for now, "vacuumdb -Zt 'pg_am(amname);CHECKPOINT'" still performs a checkpoint. Back-patch to 9.3 (all supported versions). Reviewed by Tom Lane, though this fix strategy was not his first choice. Reported by Arseniy Sharoglazov. Security: CVE-2018-1058
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.