[stable-2.6] avoid loading vars on unspecified basedir (cwd) (#42067)

* avoid loading vars on unspecified basedir (cwd)
(cherry picked from commit de0e11c)

Co-authored-by: Brian Coca <bcoca@users.noreply.github.com>

changelogs/fragments/avoid_cwd_vars.yml

@@ -0,0 +1,2 @@
+bugfixes:
+    - '**Security Fix** - avoid loading host/group vars from cwd when not specifying a playbook or playbook base dir'

lib/ansible/cli/__init__.py

@@ -664,7 +664,7 @@ class CLI(with_metaclass(ABCMeta, object)):
                 ansible_versions[counter] = 0
             try:
                 ansible_versions[counter] = int(ansible_versions[counter])
-            except:
+            except Exception:
                 pass
         if len(ansible_versions) < 3:
             for counter in range(len(ansible_versions), 3):
@@ -809,6 +809,12 @@ class CLI(with_metaclass(ABCMeta, object)):
         # the code, ensuring a consistent view of global variables
         variable_manager = VariableManager(loader=loader, inventory=inventory)
 
+        if hasattr(options, 'basedir'):
+            if options.basedir:
+                variable_manager.safe_basedir = True
+        else:
+            variable_manager.safe_basedir = True
+
         # load vars from cli options
         variable_manager.extra_vars = load_extra_vars(loader=loader, options=options)
         variable_manager.options_vars = load_options_vars(options, CLI.version_info(gitinfo=False))

lib/ansible/vars/manager.py

@@ -90,6 +90,7 @@ class VariableManager:
         self._hostvars = None
         self._omit_token = '__omit_place_holder__%s' % sha1(os.urandom(64)).hexdigest()
         self._options_vars = defaultdict(dict)
+        self.safe_basedir = False
 
         # bad cache plugin is not fatal error
         try:
@@ -110,6 +111,7 @@ class VariableManager:
             omit_token=self._omit_token,
             options_vars=self._options_vars,
             inventory=self._inventory,
+            safe_basedir=self.safe_basedir,
         )
         return data
 
@@ -123,6 +125,7 @@ class VariableManager:
         self._omit_token = data.get('omit_token', '__omit_place_holder__%s' % sha1(os.urandom(64)).hexdigest())
         self._inventory = data.get('inventory', None)
         self._options_vars = data.get('options_vars', dict())
+        self.safe_basedir = data.get('safe_basedir', False)
 
     @property
     def extra_vars(self):
@@ -183,7 +186,9 @@ class VariableManager:
         )
 
         # default for all cases
-        basedirs = [self._loader.get_basedir()]
+        basedirs = []
+        if self.safe_basedir:  # avoid adhoc/console loading cwd
+            basedirs = [self._loader.get_basedir()]
 
         if play:
             # first we compile any vars specified in defaults/main.yml