summaryrefslogtreecommitdiff
blob: 135fdc2747818c9c996030bc6df79fc1bab2523c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
From ed56f51f185a1ffd7ea57130d260098686fcc7c2 Mon Sep 17 00:00:00 2001
From: James Cammarata <jimi@sngx.net>
Date: Mon, 8 May 2017 10:37:10 -0500
Subject: [PATCH] Fixing security issue with lookup returns not tainting the
 jinja2 environment

CVE-2017-7481

Lookup returns wrap the result in unsafe, however when used through the
standard templar engine, this does not result in the jinja2 environment being
marked as unsafe as a whole. This means the lookup result looses the unsafe
protection and may become simple unicode strings, which can result in bad
things being re-templated.

This also adds a global lookup param and cfg options for lookups to allow
unsafe returns, so users can force the previous (insecure) behavior.
---
 docs/docsite/rst/intro_configuration.rst | 14 ++++++++++++++
 examples/ansible.cfg                     |  8 +++++++-
 lib/ansible/constants.py                 |  1 +
 lib/ansible/template/__init__.py         | 11 +++++++++--
 4 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/docs/docsite/rst/intro_configuration.rst b/docs/docsite/rst/intro_configuration.rst
index 3647e22..259e107 100644
--- a/docs/docsite/rst/intro_configuration.rst
+++ b/docs/docsite/rst/intro_configuration.rst
@@ -86,6 +86,20 @@ different locations::
 Most users will not need to use this feature.  See :doc:`dev_guide/developing_plugins` for more details.
 
 
+.. _allow_unsafe_lookups:
+
+allow_unsafe_lookups
+====================
+
+.. versionadded:: 2.2.3, 2.3.1
+
+When enabled, this option allows lookup plugins (whether used in variables as `{{lookup('foo')}}` or as a loop as `with_foo`) to return data that is **not** marked "unsafe". By default, such data is marked as unsafe to prevent the templating engine from evaluating any jinja2 templating language, as this could represent a security risk.
+
+This option is provided to allow for backwards-compatibility, however users should first consider adding `allow_unsafe=True` to any lookups which may be expected to contain data which may be run through the templating engine later. For example::
+
+    {{lookup('pipe', '/path/to/some/command', allow_unsafe=True)}}
+
+
 .. _allow_world_readable_tmpfiles:
 
 allow_world_readable_tmpfiles
diff --git a/examples/ansible.cfg b/examples/ansible.cfg
index e283064..77ba5d2 100644
--- a/examples/ansible.cfg
+++ b/examples/ansible.cfg
@@ -282,7 +282,7 @@
 # Controls showing custom stats at the end, off by default
 #show_custom_stats = True
 
-# Controlls which files to ignore when using a directory as inventory with
+# Controls which files to ignore when using a directory as inventory with
 # possibly multiple sources (both static and dynamic)
 #inventory_ignore_extensions = ~, .orig, .bak, .ini, .cfg, .retry, .pyc, .pyo
 
@@ -294,6 +294,12 @@
 # Setting to True keeps them under the ansible_facts namespace, the default is False
 #restrict_facts_namespace: True
 
+# When enabled, this option allows lookups (via variables like {{lookup('foo')}} or when used as
+# a loop with `with_foo`) to return data that is not marked "unsafe". This means the data may contain
+# jinja2 templating language which will be run through the templating engine.
+# ENABLING THIS COULD BE A SECURITY RISK
+#allow_unsafe_lookups = False
+
 [privilege_escalation]
 #become=True
 #become_method=sudo
diff --git a/lib/ansible/constants.py b/lib/ansible/constants.py
index da45037..40d1038 100644
--- a/lib/ansible/constants.py
+++ b/lib/ansible/constants.py
@@ -236,6 +236,7 @@ def load_config_file():
                                        ["~", ".orig", ".bak", ".ini", ".cfg", ".retry", ".pyc", ".pyo"], value_type='list')
 DEFAULT_VAR_COMPRESSION_LEVEL = get_config(p, DEFAULTS, 'var_compression_level', 'ANSIBLE_VAR_COMPRESSION_LEVEL', 0, value_type='integer')
 DEFAULT_INTERNAL_POLL_INTERVAL = get_config(p, DEFAULTS, 'internal_poll_interval', None, 0.001, value_type='float')
+DEFAULT_ALLOW_UNSAFE_LOOKUPS = get_config(p, DEFAULTS, 'allow_unsafe_lookups', None, False, value_type='boolean')
 ERROR_ON_MISSING_HANDLER  = get_config(p, DEFAULTS, 'error_on_missing_handler', 'ANSIBLE_ERROR_ON_MISSING_HANDLER', True, value_type='boolean')
 SHOW_CUSTOM_STATS = get_config(p, DEFAULTS, 'show_custom_stats', 'ANSIBLE_SHOW_CUSTOM_STATS', False, value_type='boolean')
 NAMESPACE_FACTS = get_config(p, DEFAULTS, 'restrict_facts_namespace', 'ANSIBLE_RESTRICT_FACTS', False, value_type='boolean')
diff --git a/lib/ansible/template/__init__.py b/lib/ansible/template/__init__.py
index 5d551d7..49de8aa 100644
--- a/lib/ansible/template/__init__.py
+++ b/lib/ansible/template/__init__.py
@@ -252,6 +252,9 @@ def __init__(self, loader, shared_loader_obj=None, variables=dict()):
             loader=FileSystemLoader(self._basedir),
         )
 
+        # the current rendering context under which the templar class is working
+        self.cur_context = None
+
         self.SINGLE_VAR = re.compile(r"^%s\s*(\w*)\s*%s$" % (self.environment.variable_start_string, self.environment.variable_end_string))
 
         self._clean_regex   = re.compile(r'(?:%s|%s|%s|%s)' % (
@@ -574,6 +577,7 @@ def _lookup(self, name, *args, **kwargs):
 
         if instance is not None:
             wantlist = kwargs.pop('wantlist', False)
+            allow_unsafe = kwargs.pop('allow_unsafe', C.DEFAULT_ALLOW_UNSAFE_LOOKUPS)
 
             from ansible.utils.listify import listify_lookup_plugin_terms
             loop_terms = listify_lookup_plugin_terms(terms=args, templar=self, loader=self._loader, fail_on_undefined=True, convert_bare=False)
@@ -510,7 +510,7 @@
                     raise AnsibleError("An unhandled exception occurred while running the lookup plugin '%s'. Error was a %s, original message: %s" % (name, type(e), e))
                 ran = None
 
-            if ran:
+            if ran and not allow_unsafe:
                 from ansible.vars.unsafe_proxy import UnsafeProxy, wrap_var
                 if wantlist:
                     ran = wrap_var(ran)
@@ -600,6 +605,8 @@ def _lookup(self, name, *args, **kwargs):
                         else:
                             ran = wrap_var(ran)
 
+                if self.cur_context:
+                    self.cur_context.unsafe = True
             return ran
         else:
             raise AnsibleError("lookup plugin (%s) not found" % name)
@@ -656,7 +663,7 @@ def do_template(self, data, preserve_trailing_newlines=True, escape_backslashes=
 
             jvars = AnsibleJ2Vars(self, t.globals)
 
-            new_context = t.new_context(jvars, shared=True)
+            self.cur_context = new_context = t.new_context(jvars, shared=True)
             rf = t.root_render_func(new_context)
 
             try: