From 2df1f7886e9e87face85569d5794ba690932c382 Mon Sep 17 00:00:00 2001 From: Lumir Balhar Date: Wed, 22 Jan 2025 12:37:29 +0100 Subject: [PATCH] CVE-2024-56326 --- Jinja2-2.10.1/jinja2/sandbox.py | 65 +++++++++++++++------------- Jinja2-2.10.1/tests/test_security.py | 17 ++++++++ 2 files changed, 53 insertions(+), 29 deletions(-) diff --git a/Jinja2-2.10.1/jinja2/sandbox.py b/Jinja2-2.10.1/jinja2/sandbox.py index 752e812..5516f96 100644 --- a/Jinja2-2.10.1/jinja2/sandbox.py +++ b/Jinja2-2.10.1/jinja2/sandbox.py @@ -15,6 +15,7 @@ import types import operator from collections import Mapping +from functools import update_wrapper from jinja2.environment import Environment from jinja2.exceptions import SecurityError from jinja2._compat import string_types, PY2 @@ -134,16 +135,6 @@ class _MagicFormatMapping(Mapping): return len(self._kwargs) -def inspect_format_method(callable): - if not isinstance(callable, (types.MethodType, - types.BuiltinMethodType)) or \ - callable.__name__ not in ('format', 'format_map'): - 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 MAX_RANGE items. @@ -372,6 +363,9 @@ class SandboxedEnvironment(Environment): except AttributeError: pass else: + fmt = self.wrap_str_format(value) + if fmt is not None: + return fmt if self.is_safe_attribute(obj, argument, value): return value return self.unsafe_undefined(obj, argument) @@ -389,6 +383,9 @@ class SandboxedEnvironment(Environment): except (TypeError, LookupError): pass else: + fmt = self.wrap_str_format(value) + if fmt is not None: + return fmt if self.is_safe_attribute(obj, attribute, value): return value return self.unsafe_undefined(obj, attribute) @@ -402,34 +399,44 @@ class SandboxedEnvironment(Environment): obj.__class__.__name__ ), name=attribute, obj=obj, exc=SecurityError) - def format_string(self, s, args, kwargs, format_func=None): - """If a format call is detected, then this is routed through this - method so that our safety sandbox can be used for it. + def wrap_str_format(self, value): + """If the given value is a ``str.format`` or ``str.format_map`` method, + return a new function than handles sandboxing. This is done at access + rather than in :meth:`call`, so that calls made without ``call`` are + also sandboxed. """ - if isinstance(s, Markup): - formatter = SandboxedEscapeFormatter(self, s.escape) + if not isinstance( + value, (types.MethodType, types.BuiltinMethodType) + ) or value.__name__ not in ("format", "format_map"): + return None + f_self = value.__self__ + if not isinstance(f_self, str): + return None + str_type = type(f_self) + is_format_map = value.__name__ == "format_map" + if isinstance(f_self, Markup): + formatter = SandboxedEscapeFormatter(self, escape=f_self.escape) else: formatter = SandboxedFormatter(self) - if format_func is not None and format_func.__name__ == 'format_map': - if len(args) != 1 or kwargs: - raise TypeError( - 'format_map() takes exactly one argument %d given' - % (len(args) + (kwargs is not None)) - ) + vformat = formatter.vformat + def wrapper(*args, **kwargs): + if is_format_map: + if kwargs: + raise TypeError("format_map() takes no keyword arguments") + if len(args) != 1: + raise TypeError( + f"format_map() takes exactly one argument ({len(args)} given)" + ) + kwargs = args[0] + args = () - kwargs = args[0] - args = None + return str_type(vformat(f_self, args, kwargs)) - kwargs = _MagicFormatMapping(args, kwargs) - rv = formatter.vformat(s, args, kwargs) - return type(s)(rv) + return update_wrapper(wrapper, value) 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, __obj) # the double prefixes are to avoid double keyword argument # errors when proxying the call. diff --git a/Jinja2-2.10.1/tests/test_security.py b/Jinja2-2.10.1/tests/test_security.py index 5c8639c..1719644 100644 --- a/Jinja2-2.10.1/tests/test_security.py +++ b/Jinja2-2.10.1/tests/test_security.py @@ -206,3 +206,20 @@ class TestStringFormatMap(object): env = SandboxedEnvironment() t = env.from_string('{{ ("a{x.foo}b{y}"|safe).format_map({"x":{"foo": 42}, "y":""}) }}') assert t.render() == 'a42b<foo>' + + def test_indirect_call(self): + def run(value, arg): + return value.run(arg) + + env = SandboxedEnvironment() + env.filters["run"] = run + t = env.from_string( + """{% set + ns = namespace(run="{0.__call__.__builtins__[__import__]}".format) + %} + {{ ns | run(not_here) }} + """ + ) + + with pytest.raises(SecurityError): + t.render() -- 2.48.0