diff --git a/jinja2/nodes.py b/jinja2/nodes.py
index c5697e6..9465943 100644
--- a/jinja2/nodes.py
+++ b/jinja2/nodes.py
@@ -599,7 +599,7 @@ class Call(Expr):
def as_const(self, eval_ctx=None):
eval_ctx = get_eval_context(self, eval_ctx)
- if eval_ctx.volatile:
+ if eval_ctx.volatile or eval_ctx.environment.sandboxed:
raise Impossible()
obj = self.node.as_const(eval_ctx)
diff --git a/jinja2/sandbox.py b/jinja2/sandbox.py
index da479c1..7e31a7a 100644
--- a/jinja2/sandbox.py
+++ b/jinja2/sandbox.py
@@ -12,12 +12,19 @@
:copyright: (c) 2010 by the Jinja Team.
:license: BSD.
"""
+import types
import operator
+from collections import Mapping
from jinja2.environment import Environment
from jinja2.exceptions import SecurityError
from jinja2._compat import string_types, function_type, method_type, \
- traceback_type, code_type, frame_type, generator_type, PY2
+ traceback_type, code_type, frame_type, generator_type, text_type, PY2
+from jinja2.utils import Markup
+has_format = False
+if hasattr(text_type, 'format'):
+ from string import Formatter
+ has_format = True
#: maximum number of items a range may produce
MAX_RANGE = 100000
@@ -32,6 +39,12 @@ UNSAFE_METHOD_ATTRIBUTES = set(['im_class', 'im_func', 'im_self'])
#: unsafe generator attirbutes.
UNSAFE_GENERATOR_ATTRIBUTES = set(['gi_frame', 'gi_code'])
+#: unsafe attributes on coroutines
+UNSAFE_COROUTINE_ATTRIBUTES = set(['cr_frame', 'cr_code'])
+
+#: unsafe attributes on async generators
+UNSAFE_ASYNC_GENERATOR_ATTRIBUTES = set(['ag_code', 'ag_frame'])
+
# On versions > python 2 the special attributes on functions are gone,
# but they remain on methods and generators for whatever reason.
if not PY2:
@@ -92,6 +105,79 @@ _mutable_spec = (
]))
)
+# Bundled EscapeFormatter class from markupsafe >= 0.21 which is used by
+# jinja2 for fixing CVE-2016-10745
+# Copyright 2010 Pallets
+# BSD 3-Clause License
+# https://github.com/pallets/markupsafe/blob/79ee6ce0ed93c6da73512f069d7db866d955df04/LICENSE.rst
+if hasattr(text_type, "format"):
+
+ class EscapeFormatter(Formatter):
+ def __init__(self, escape):
+ self.escape = escape
+
+ def format_field(self, value, format_spec):
+ if hasattr(value, "__html_format__"):
+ rv = value.__html_format__(format_spec)
+ elif hasattr(value, "__html__"):
+ if format_spec:
+ raise ValueError(
+ "Format specifier {0} given, but {1} does not"
+ " define __html_format__. A class that defines"
+ " __html__ must define __html_format__ to work"
+ " with format specifiers.".format(format_spec, type(value))
+ )
+ rv = value.__html__()
+ else:
+ # We need to make sure the format spec is unicode here as
+ # otherwise the wrong callback methods are invoked. For
+ # instance a byte string there would invoke __str__ and
+ # not __unicode__.
+ rv = Formatter.format_field(self, value, text_type(format_spec))
+ return text_type(self.escape(rv))
+
+class _MagicFormatMapping(Mapping):
+ """This class implements a dummy wrapper to fix a bug in the Python
+ standard library for string formatting.
+
+ See http://bugs.python.org/issue13598 for information about why
+ this is necessary.
+ """
+
+ def __init__(self, args, kwargs):
+ self._args = args
+ self._kwargs = kwargs
+ self._last_index = 0
+
+ def __getitem__(self, key):
+ if key == '':
+ idx = self._last_index
+ self._last_index += 1
+ try:
+ return self._args[idx]
+ except LookupError:
+ pass
+ key = str(idx)
+ return self._kwargs[key]
+
+ def __iter__(self):
+ return iter(self._kwargs)
+
+ def __len__(self):
+ return len(self._kwargs)
+
+
+def inspect_format_method(callable):
+ if not has_format:
+ return None
+ if not isinstance(callable, (types.MethodType,
+ types.BuiltinMethodType)) or \
+ callable.__name__ != 'format':
+ return None
+ obj = callable.__self__
+ if isinstance(obj, string_types):
+ return obj
+
def safe_range(*args):
"""A range that can't generate ranges with a length of more than
@@ -146,6 +232,12 @@ def is_internal_attribute(obj, attr):
elif isinstance(obj, generator_type):
if attr in UNSAFE_GENERATOR_ATTRIBUTES:
return True
+ elif hasattr(types, 'CoroutineType') and isinstance(obj, types.CoroutineType):
+ if attr in UNSAFE_COROUTINE_ATTRIBUTES:
+ return True
+ elif hasattr(types, 'AsyncGeneratorType') and isinstance(obj, types.AsyncGeneratorType):
+ if attri in UNSAFE_ASYNC_GENERATOR_ATTRIBUTES:
+ return True
return attr.startswith('__')
@@ -184,8 +276,8 @@ class SandboxedEnvironment(Environment):
attributes or functions are safe to access.
If the template tries to access insecure code a :exc:`SecurityError` is
- raised. However also other exceptions may occour during the rendering so
- the caller has to ensure that all exceptions are catched.
+ raised. However also other exceptions may occur during the rendering so
+ the caller has to ensure that all exceptions are caught.
"""
sandboxed = True
@@ -347,8 +439,24 @@ class SandboxedEnvironment(Environment):
obj.__class__.__name__
), name=attribute, obj=obj, exc=SecurityError)
+ def format_string(self, s, args, kwargs):
+ """If a format call is detected, then this is routed through this
+ method so that our safety sandbox can be used for it.
+ """
+ if isinstance(s, Markup):
+ formatter = SandboxedEscapeFormatter(self, s.escape)
+ else:
+ formatter = SandboxedFormatter(self)
+ kwargs = _MagicFormatMapping(args, kwargs)
+ rv = formatter.vformat(s, args, kwargs)
+ return type(s)(rv)
+
def call(__self, __context, __obj, *args, **kwargs):
"""Call an object from sandboxed code."""
+ fmt = inspect_format_method(__obj)
+ if fmt is not None:
+ return __self.format_string(fmt, args, kwargs)
+
# the double prefixes are to avoid double keyword argument
# errors when proxying the call.
if not __self.is_safe_callable(__obj):
@@ -366,3 +474,37 @@ class ImmutableSandboxedEnvironment(SandboxedEnvironment):
if not SandboxedEnvironment.is_safe_attribute(self, obj, attr, value):
return False
return not modifies_known_mutable(obj, attr)
+
+
+if has_format:
+ # This really is not a public API apparenlty.
+ try:
+ from _string import formatter_field_name_split
+ except ImportError:
+ def formatter_field_name_split(field_name):
+ return field_name._formatter_field_name_split()
+
+ class SandboxedFormatterMixin(object):
+
+ def __init__(self, env):
+ self._env = env
+
+ def get_field(self, field_name, args, kwargs):
+ first, rest = formatter_field_name_split(field_name)
+ obj = self.get_value(first, args, kwargs)
+ for is_attr, i in rest:
+ if is_attr:
+ obj = self._env.getattr(obj, i)
+ else:
+ obj = self._env.getitem(obj, i)
+ return obj, first
+
+ class SandboxedFormatter(SandboxedFormatterMixin, Formatter):
+ def __init__(self, env):
+ SandboxedFormatterMixin.__init__(self, env)
+ Formatter.__init__(self)
+
+ class SandboxedEscapeFormatter(SandboxedFormatterMixin, EscapeFormatter):
+ def __init__(self, env, escape):
+ SandboxedFormatterMixin.__init__(self, env)
+ EscapeFormatter.__init__(self, escape)