Security fix for CVE-2025-27516

Resolves: RHEL-85063

0006-CVE-2025-27516.patch

@@ -0,0 +1,87 @@
+From c630659347e6824a303e63a7706c23d248bf17cc Mon Sep 17 00:00:00 2001
+From: Lumir Balhar <lbalhar@redhat.com>
+Date: Wed, 26 Mar 2025 21:51:37 +0100
+Subject: [PATCH] CVE-2025-27516
+
+---
+ src/jinja2/filters.py  | 34 ++++++++++++++++------------------
+ tests/test_security.py | 10 ++++++++++
+ 2 files changed, 26 insertions(+), 18 deletions(-)
+
+diff --git a/src/jinja2/filters.py b/src/jinja2/filters.py
+index 6d4f348..bc6cab3 100644
+--- a/src/jinja2/filters.py
++++ b/src/jinja2/filters.py
+@@ -5,6 +5,7 @@ import random
+ import re
+ import warnings
+ from collections import namedtuple
++from inspect import getattr_static
+ from itertools import chain
+ from itertools import groupby
+ 
+@@ -1067,28 +1068,25 @@ def do_reverse(value):
+ 
+ @environmentfilter
+ def do_attr(environment, obj, name):
+-    """Get an attribute of an object.  ``foo|attr("bar")`` works like
+-    ``foo.bar`` just that always an attribute is returned and items are not
+-    looked up.
++    """Get an attribute of an object. ``foo|attr("bar")`` works like
++    ``foo.bar``, but returns undefined instead of falling back to ``foo["bar"]``
++    if the attribute doesn't exist.
+ 
+     See :ref:`Notes on subscriptions <notes-on-subscriptions>` for more details.
+     """
++    # Environment.getattr will fall back to obj[name] if obj.name doesn't exist.
++    # But we want to call env.getattr to get behavior such as sandboxing.
++    # Determine if the attr exists first, so we know the fallback won't trigger.
+     try:
+-        name = str(name)
+-    except UnicodeError:
+-        pass
+-    else:
+-        try:
+-            value = getattr(obj, name)
+-        except AttributeError:
+-            pass
+-        else:
+-            if environment.sandboxed and not environment.is_safe_attribute(
+-                obj, name, value
+-            ):
+-                return environment.unsafe_undefined(obj, name)
+-            return value
+-    return environment.undefined(obj=obj, name=name)
++        # This avoids executing properties/descriptors, but misses __getattr__
++        # and __getattribute__ dynamic attrs.
++        getattr_static(obj, name)
++    except AttributeError:
++        # This finds dynamic attrs, and we know it's not a descriptor at this point.
++        if not hasattr(obj, name):
++            return environment.undefined(obj=obj, name=name)
++
++    return environment.getattr(obj, name)
+ 
+ 
+ @contextfilter
+diff --git a/tests/test_security.py b/tests/test_security.py
+index 2e2af69..c1c71df 100644
+--- a/tests/test_security.py
++++ b/tests/test_security.py
+@@ -225,3 +225,13 @@ class TestStringFormatMap(object):
+ 
+         with pytest.raises(SecurityError):
+             t.render()
++
++    def test_attr_filter(self) -> None:
++        env = SandboxedEnvironment()
++        t = env.from_string(
++            """{{ "{0.__call__.__builtins__[__import__]}"
++                  | attr("format")(not_here) }}"""
++        )
++
++        with pytest.raises(SecurityError):
++            t.render()
+-- 
+2.49.0
+

python-jinja2.spec

@@ -2,7 +2,7 @@
 
 Name:           python-jinja2
 Version:        2.11.3
-Release:        7%{?dist}
+Release:        8%{?dist}
 Summary:        General purpose template engine
 License:        BSD
 URL:            https://palletsprojects.com/p/jinja/
@@ -25,6 +25,12 @@ Patch4:         0004-CVE-2024-34064.patch
 # Patch backported from upstream without changelog and typing.
 Patch5:         0005-CVE-2024-56326.patch
 
+# Security fix for CVE-2025-27516
+# Resolved upstream: https://github.com/pallets/jinja/commit/90457bbf33b8662926ae65cdde4c4c32e756e403
+# Tracking bug: https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2025-27516
+# Patch backported from upstream without changelog.
+Patch6:         0006-CVE-2025-27516.patch
+
 %if 0%{?fedora} || 0%{?rhel} > 7
 # Enable python3 build by default
 %bcond_without python3
@@ -196,6 +202,10 @@ PYTHONPATH=$(pwd)/src %{__python3} -m pytest tests
 
 
 %changelog
+* Wed Mar 26 2025 Lumír Balhar <lbalhar@redhat.com> - 2.11.3-8
+- Security fix for CVE-2025-27516
+Resolves: RHEL-85063
+
 * Wed Jan 22 2025 Lumír Balhar <lbalhar@redhat.com> - 2.11.3-7
 - Security fix for CVE-2024-56326
 Resolves: RHEL-74690