</para>
<para>
- However, if you are upgrading from a version earlier than 9.2.20,
+ However, if you use foreign data servers that make use of user
+ passwords for authentication, see the first changelog entry below.
+ </para>
+
+ <para>
+ Also, if you are upgrading from a version earlier than 9.2.20,
see <xref linkend="release-9-2-20">.
</para>
<itemizedlist>
+ <listitem>
+ <para>
+ Further restrict visibility
+ of <structname>pg_user_mappings</>.<structfield>umoptions</>, to
+ protect passwords stored as user mapping options
+ (Noah Misch)
+ </para>
+
+ <para>
+ The fix for CVE-2017-7486 was incorrect: it allowed a user
+ to see the options in her own user mapping, even if she did not
+ have <literal>USAGE</> permission on the associated foreign server.
+ Such options might include a password that had been provided by the
+ server owner rather than the user herself.
+ Since <structname>information_schema.user_mapping_options</> does not
+ show the options in such cases, <structname>pg_user_mappings</>
+ should not either.
+ (CVE-2017-7547)
+ </para>
+
+ <para>
+ By itself, this patch will only fix the behavior in newly initdb'd
+ databases. If you wish to apply this change in an existing database,
+ you will need to do the following:
+ </para>
+
+ <procedure>
+ <step>
+ <para>
+ Restart the postmaster after adding <literal>allow_system_table_mods
+ = true</> to <filename>postgresql.conf</>. (In versions
+ supporting <command>ALTER SYSTEM</>, you can use that to make the
+ configuration change, but you'll still need a restart.)
+ </para>
+ </step>
+
+ <step>
+ <para>
+ In <emphasis>each</> database of the cluster,
+ run the following commands as superuser:
+<programlisting>
+SET search_path = pg_catalog;
+CREATE OR REPLACE VIEW pg_user_mappings AS
+ SELECT
+ U.oid AS umid,
+ S.oid AS srvid,
+ S.srvname AS srvname,
+ U.umuser AS umuser,
+ CASE WHEN U.umuser = 0 THEN
+ 'public'
+ ELSE
+ A.rolname
+ END AS usename,
+ CASE WHEN (U.umuser <> 0 AND A.rolname = current_user
+ AND (pg_has_role(S.srvowner, 'USAGE')
+ OR has_server_privilege(S.oid, 'USAGE')))
+ 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);
+</programlisting>
+ </para>
+ </step>
+
+ <step>
+ <para>
+ Do not forget to include the <literal>template0</>
+ and <literal>template1</> databases, or the vulnerability will still
+ exist in databases you create later. To fix <literal>template0</>,
+ you'll need to temporarily make it accept connections.
+ In <productname>PostgreSQL</> 9.5 and later, you can use
+<programlisting>
+ALTER DATABASE template0 WITH ALLOW_CONNECTIONS true;
+</programlisting>
+ and then after fixing <literal>template0</>, undo that with
+<programlisting>
+ALTER DATABASE template0 WITH ALLOW_CONNECTIONS false;
+</programlisting>
+ In prior versions, instead use
+<programlisting>
+UPDATE pg_database SET datallowconn = true WHERE datname = 'template0';
+UPDATE pg_database SET datallowconn = false WHERE datname = 'template0';
+</programlisting>
+ </para>
+ </step>
+
+ <step>
+ <para>
+ Finally, remove the <literal>allow_system_table_mods</> configuration
+ setting, and again restart the postmaster.
+ </para>
+ </step>
+ </procedure>
+ </listitem>
+
+ <listitem>
+ <para>
+ Disallow empty passwords in all password-based authentication methods
+ (Heikki Linnakangas)
+ </para>
+
+ <para>
+ <application>libpq</> ignores empty password specifications, and does
+ not transmit them to the server. So, if a user's password has been
+ set to the empty string, it's impossible to log in with that password
+ via <application>psql</> or other <application>libpq</>-based
+ clients. An administrator might therefore believe that setting the
+ password to empty is equivalent to disabling password login.
+ However, with a modified or non-<application>libpq</>-based client,
+ logging in could be possible, depending on which authentication
+ method is configured. In particular the most common
+ method, <literal>md5</>, accepted empty passwords.
+ Change the server to reject empty passwords in all cases.
+ (CVE-2017-7546)
+ </para>
+ </listitem>
+
<listitem>
<para>
On Windows, retry process creation if we fail to reserve the address
<para>
By itself, this patch will only fix the behavior in newly initdb'd
databases. If you wish to apply this change in an existing database,
- you will need to do the following:
+ follow the corrected procedure shown in the changelog entry for
+ CVE-2017-7547, in <xref linkend="release-9-2-22">.
</para>
-
- <procedure>
- <step>
- <para>
- Restart the postmaster after adding <literal>allow_system_table_mods
- = true</> to <filename>postgresql.conf</>. (In versions
- supporting <command>ALTER SYSTEM</>, you can use that to make the
- configuration change, but you'll still need a restart.)
- </para>
- </step>
-
- <step>
- <para>
- In <emphasis>each</> database of the cluster,
- run the following commands as superuser:
-<programlisting>
-SET search_path = pg_catalog;
-CREATE OR REPLACE VIEW pg_user_mappings AS
- SELECT
- U.oid AS umid,
- S.oid AS srvid,
- S.srvname AS srvname,
- U.umuser AS umuser,
- CASE WHEN U.umuser = 0 THEN
- 'public'
- ELSE
- A.rolname
- END AS usename,
- 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);
-</programlisting>
- </para>
- </step>
-
- <step>
- <para>
- Do not forget to include the <literal>template0</>
- and <literal>template1</> databases, or the vulnerability will still
- exist in databases you create later. To fix <literal>template0</>,
- you'll need to temporarily make it accept connections.
- In <productname>PostgreSQL</> 9.5 and later, you can use
-<programlisting>
-ALTER DATABASE template0 WITH ALLOW_CONNECTIONS true;
-</programlisting>
- and then after fixing <literal>template0</>, undo that with
-<programlisting>
-ALTER DATABASE template0 WITH ALLOW_CONNECTIONS false;
-</programlisting>
- In prior versions, instead use
-<programlisting>
-UPDATE pg_database SET datallowconn = true WHERE datname = 'template0';
-UPDATE pg_database SET datallowconn = false WHERE datname = 'template0';
-</programlisting>
- </para>
- </step>
-
- <step>
- <para>
- Finally, remove the <literal>allow_system_table_mods</> configuration
- setting, and again restart the postmaster.
- </para>
- </step>
- </procedure>
</listitem>
<listitem>
projects / postgresql-pgindent.git / commitdiff