Fix broken escaping logic for "pg_dump_command" (#822) + bonus shell injection fixes.

NEWS

@@ -1,9 +1,11 @@
-1.8.8.dev0
+1.8.8
  * #370: For the PostgreSQL hook, pass the "PGSSLMODE" environment variable through to Borg when the
    database's configuration omits the "ssl_mode" option.
  * #818: Allow the "--repository" flag to match across multiple configuration files.
  * #820: Fix broken repository detection in the "rcreate" action with Borg 1.4. The issue did not
    occur with other versions of Borg.
+ * #822: Fix broken escaping logic in the PostgreSQL hook's "pg_dump_command" option.
+ * SECURITY: Prevent additional shell injection attacks within the PostgreSQL hook.
 
 1.8.7
  * #736: Store included configuration files within each backup archive in support of the "config

borgmatic/hooks/postgresql.py

@@ -73,9 +73,11 @@ def database_names_to_dump(database, extra_environment, log_prefix, dry_run):
     if dry_run:
         return ()
 
-    psql_command = shlex.split(database.get('psql_command') or 'psql')
+    psql_command = tuple(
+        shlex.quote(part) for part in shlex.split(database.get('psql_command') or 'psql')
+    )
     list_command = (
-        tuple(psql_command)
+        psql_command
         + ('--list', '--no-password', '--no-psqlrc', '--csv', '--tuples-only')
         + (('--host', database['hostname']) if 'hostname' in database else ())
         + (('--port', str(database['port'])) if 'port' in database else ())
@@ -127,7 +129,10 @@ def dump_data_sources(databases, config, log_prefix, dry_run):
         for database_name in dump_database_names:
             dump_format = database.get('format', None if database_name == 'all' else 'custom')
             default_dump_command = 'pg_dumpall' if database_name == 'all' else 'pg_dump'
-            dump_command = database.get('pg_dump_command') or default_dump_command
+            dump_command = tuple(
+                shlex.quote(part)
+                for part in shlex.split(database.get('pg_dump_command') or default_dump_command)
+            )
             dump_filename = dump.make_data_source_dump_filename(
                 dump_path, database_name, database.get('hostname')
             )
@@ -138,8 +143,8 @@ def dump_data_sources(databases, config, log_prefix, dry_run):
                 continue
 
             command = (
-                (
+                dump_command
-                    shlex.quote(dump_command),
+                + (
                     '--no-password',
                     '--clean',
                     '--if-exists',
@@ -242,9 +247,11 @@ def restore_data_source_dump(
     dump_filename = dump.make_data_source_dump_filename(
         make_dump_path(config), data_source['name'], data_source.get('hostname')
     )
-    psql_command = shlex.split(data_source.get('psql_command') or 'psql')
+    psql_command = tuple(
+        shlex.quote(part) for part in shlex.split(data_source.get('psql_command') or 'psql')
+    )
     analyze_command = (
-        tuple(psql_command)
+        psql_command
         + ('--no-password', '--no-psqlrc', '--quiet')
         + (('--host', hostname) if hostname else ())
         + (('--port', port) if port else ())
@@ -258,9 +265,12 @@ def restore_data_source_dump(
         + ('--command', 'ANALYZE')
     )
     use_psql_command = all_databases or data_source.get('format') == 'plain'
-    pg_restore_command = shlex.split(data_source.get('pg_restore_command') or 'pg_restore')
+    pg_restore_command = tuple(
+        shlex.quote(part)
+        for part in shlex.split(data_source.get('pg_restore_command') or 'pg_restore')
+    )
     restore_command = (
-        tuple(psql_command if use_psql_command else pg_restore_command)
+        (psql_command if use_psql_command else pg_restore_command)
         + ('--no-password',)
         + (('--no-psqlrc',) if use_psql_command else ('--if-exists', '--exit-on-error', '--clean'))
         + (('--dbname', data_source['name']) if not all_databases else ())

setup.py

@@ -1,6 +1,6 @@
 from setuptools import find_packages, setup
 
-VERSION = '1.8.8.dev0'
+VERSION = '1.8.8'
 
 
 setup(

tests/unit/hooks/test_postgresql.py

@@ -172,11 +172,17 @@ def test_database_names_to_dump_with_all_and_format_excludes_particular_database
 
 
 def test_database_names_to_dump_with_all_and_psql_command_uses_custom_command():
-    database = {'name': 'all', 'format': 'custom', 'psql_command': 'docker exec mycontainer psql'}
+    database = {
+        'name': 'all',
+        'format': 'custom',
+        'psql_command': 'docker exec --workdir * mycontainer psql',
+    }
     flexmock(module).should_receive('execute_command_and_capture_output').with_args(
         (
             'docker',
             'exec',
+            '--workdir',
+            "'*'",  # Should get shell escaped to prevent injection attacks.
             'mycontainer',
             'psql',
             '--list',
@@ -476,7 +482,7 @@ def test_dump_data_sources_runs_pg_dumpall_for_all_databases():
 
 
 def test_dump_data_sources_runs_non_default_pg_dump():
-    databases = [{'name': 'foo', 'pg_dump_command': 'special_pg_dump'}]
+    databases = [{'name': 'foo', 'pg_dump_command': 'special_pg_dump --compress *'}]
     process = flexmock()
     flexmock(module).should_receive('make_extra_environment').and_return({'PGSSLMODE': 'disable'})
     flexmock(module).should_receive('make_dump_path').and_return('')
@@ -490,6 +496,8 @@ def test_dump_data_sources_runs_non_default_pg_dump():
     flexmock(module).should_receive('execute_command').with_args(
         (
             'special_pg_dump',
+            '--compress',
+            "'*'",  # Should get shell escaped to prevent injection attacks.
             '--no-password',
             '--clean',
             '--if-exists',
@@ -987,8 +995,8 @@ def test_restore_data_source_dump_runs_non_default_pg_restore_and_psql():
     hook_config = [
         {
             'name': 'foo',
-            'pg_restore_command': 'docker exec mycontainer pg_restore',
+            'pg_restore_command': 'docker exec --workdir * mycontainer pg_restore',
-            'psql_command': 'docker exec mycontainer psql',
+            'psql_command': 'docker exec --workdir * mycontainer psql',
             'schemas': None,
         }
     ]
@@ -1001,6 +1009,8 @@ def test_restore_data_source_dump_runs_non_default_pg_restore_and_psql():
         (
             'docker',
             'exec',
+            '--workdir',
+            "'*'",  # Should get shell escaped to prevent injection attacks.
             'mycontainer',
             'pg_restore',
             '--no-password',
@@ -1019,6 +1029,8 @@ def test_restore_data_source_dump_runs_non_default_pg_restore_and_psql():
         (
             'docker',
             'exec',
+            '--workdir',
+            "'*'",  # Should get shell escaped to prevent injection attacks.
             'mycontainer',
             'psql',
             '--no-password',