python3-django: fix CVE-2021-28658

In Django 2.2 before 2.2.20, 3.0 before 3.0.14, and 3.1 before 3.1.8,
MultiPartParser allowed directory traversal via uploaded files with
suitably crafted file names. Built-in upload handlers were not affected
by this vulnerability.

References:
https://nvd.nist.gov/vuln/detail/CVE-2021-28658

Upstream patches:
https://github.com/django/django/commit/4036d62bda0e9e9f6172943794b744a454ca49c2

Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Trevor Gamblin <trevor.gamblin@windriver.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
(cherry picked from commit aef354a0c29a4c6aad4ace53190b5573c78d881b)
Signed-off-by: Armin Kuster <akuster808@gmail.com>

2 files changed, 291 insertions, 0 deletions

diff --git a/meta-python/recipes-devtools/python/python3-django-2.2.16/CVE-2021-28658.patch b/meta-python/recipes-devtools/python/python3-django-2.2.16/CVE-2021-28658.patch
new file mode 100644
index 0000000000..325aa00420
--- /dev/null
+++ b/meta-python/recipes-devtools/python/python3-django-2.2.16/CVE-2021-28658.patch
@@ -0,0 +1,289 @@
+From 4036d62bda0e9e9f6172943794b744a454ca49c2 Mon Sep 17 00:00:00 2001
+From: Mariusz Felisiak <felisiak.mariusz@gmail.com>
+Date: Tue, 16 Mar 2021 10:19:00 +0100
+Subject: [PATCH] Fixed CVE-2021-28658 -- Fixed potential directory-traversal
+ via uploaded files.
+
+Thanks Claude Paroz for the initial patch.
+Thanks Dennis Brinkrolf for the report.
+
+Backport of d4d800ca1addc4141e03c5440a849bb64d1582cd from main.
+
+Upstream-Status: Backport
+CVE: CVE-2021-28658
+
+Reference to upstream patch:
+[https://github.com/django/django/commit/4036d62bda0e9e9f6172943794b744a454ca49c2]
+
+[SG: Adapted stable/2.2.x patch for 2.2.16]
+Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com>
+---
+ django/http/multipartparser.py      | 13 ++++--
+ docs/releases/2.2.16.txt            | 12 +++++
+ tests/file_uploads/tests.py         | 72 ++++++++++++++++++++++-------
+ tests/file_uploads/uploadhandler.py | 31 +++++++++++++
+ tests/file_uploads/urls.py          |  1 +
+ tests/file_uploads/views.py         | 12 ++++-
+ 6 files changed, 120 insertions(+), 21 deletions(-)
+
+diff --git a/django/http/multipartparser.py b/django/http/multipartparser.py
+index f6f12ca..5a9cca8 100644
+--- a/django/http/multipartparser.py
++++ b/django/http/multipartparser.py
+@@ -7,6 +7,7 @@ file upload handlers for processing.
+ import base64
+ import binascii
+ import cgi
++import os
+ from urllib.parse import unquote
+ 
+ from django.conf import settings
+@@ -205,7 +206,7 @@ class MultiPartParser:
+                     file_name = disposition.get('filename')
+                     if file_name:
+                         file_name = force_text(file_name, encoding, errors='replace')
+-                        file_name = self.IE_sanitize(unescape_entities(file_name))
++                        file_name = self.sanitize_file_name(file_name)
+                     if not file_name:
+                         continue
+ 
+@@ -293,9 +294,13 @@ class MultiPartParser:
+                 self._files.appendlist(force_text(old_field_name, self._encoding, errors='replace'), file_obj)
+                 break
+ 
+-    def IE_sanitize(self, filename):
+-        """Cleanup filename from Internet Explorer full paths."""
+-        return filename and filename[filename.rfind("\\") + 1:].strip()
++    def sanitize_file_name(self, file_name):
++        file_name = unescape_entities(file_name)
++        # Cleanup Windows-style path separators.
++        file_name = file_name[file_name.rfind('\\') + 1:].strip()
++        return os.path.basename(file_name)
++
++    IE_sanitize = sanitize_file_name
+ 
+     def _close_files(self):
+         # Free up all file handles.
+diff --git a/docs/releases/2.2.16.txt b/docs/releases/2.2.16.txt
+index 31231fb..4b7021b 100644
+--- a/docs/releases/2.2.16.txt
++++ b/docs/releases/2.2.16.txt
+@@ -2,6 +2,18 @@
+ Django 2.2.16 release notes
+ ===========================
+ 
++*April 6, 2021*
++
++Backported from Django 2.2.20 a fix for a security issue.
++
++CVE-2021-28658: Potential directory-traversal via uploaded files
++================================================================
++
++``MultiPartParser`` allowed directory-traversal via uploaded files with
++suitably crafted file names.
++
++Built-in upload handlers were not affected by this vulnerability.
++
+ *September 1, 2020*
+ 
+ Django 2.2.16 fixes two security issues and two data loss bugs in 2.2.15.
+diff --git a/tests/file_uploads/tests.py b/tests/file_uploads/tests.py
+index ea4976d..2a08d1b 100644
+--- a/tests/file_uploads/tests.py
++++ b/tests/file_uploads/tests.py
+@@ -22,6 +22,21 @@ UNICODE_FILENAME = 'test-0123456789_中文_Orléans.jpg'
+ MEDIA_ROOT = sys_tempfile.mkdtemp()
+ UPLOAD_TO = os.path.join(MEDIA_ROOT, 'test_upload')
+ 
++CANDIDATE_TRAVERSAL_FILE_NAMES = [
++    '/tmp/hax0rd.txt',          # Absolute path, *nix-style.
++    'C:\\Windows\\hax0rd.txt',  # Absolute path, win-style.
++    'C:/Windows/hax0rd.txt',    # Absolute path, broken-style.
++    '\\tmp\\hax0rd.txt',        # Absolute path, broken in a different way.
++    '/tmp\\hax0rd.txt',         # Absolute path, broken by mixing.
++    'subdir/hax0rd.txt',        # Descendant path, *nix-style.
++    'subdir\\hax0rd.txt',       # Descendant path, win-style.
++    'sub/dir\\hax0rd.txt',      # Descendant path, mixed.
++    '../../hax0rd.txt',         # Relative path, *nix-style.
++    '..\\..\\hax0rd.txt',       # Relative path, win-style.
++    '../..\\hax0rd.txt',        # Relative path, mixed.
++    '..&#x2F;hax0rd.txt',       # HTML entities.
++]
++
+ 
+ @override_settings(MEDIA_ROOT=MEDIA_ROOT, ROOT_URLCONF='file_uploads.urls', MIDDLEWARE=[])
+ class FileUploadTests(TestCase):
+@@ -205,22 +220,8 @@ class FileUploadTests(TestCase):
+         # a malicious payload with an invalid file name (containing os.sep or
+         # os.pardir). This similar to what an attacker would need to do when
+         # trying such an attack.
+-        scary_file_names = [
+-            "/tmp/hax0rd.txt",          # Absolute path, *nix-style.
+-            "C:\\Windows\\hax0rd.txt",  # Absolute path, win-style.
+-            "C:/Windows/hax0rd.txt",    # Absolute path, broken-style.
+-            "\\tmp\\hax0rd.txt",        # Absolute path, broken in a different way.
+-            "/tmp\\hax0rd.txt",         # Absolute path, broken by mixing.
+-            "subdir/hax0rd.txt",        # Descendant path, *nix-style.
+-            "subdir\\hax0rd.txt",       # Descendant path, win-style.
+-            "sub/dir\\hax0rd.txt",      # Descendant path, mixed.
+-            "../../hax0rd.txt",         # Relative path, *nix-style.
+-            "..\\..\\hax0rd.txt",       # Relative path, win-style.
+-            "../..\\hax0rd.txt"         # Relative path, mixed.
+-        ]
+-
+         payload = client.FakePayload()
+-        for i, name in enumerate(scary_file_names):
++        for i, name in enumerate(CANDIDATE_TRAVERSAL_FILE_NAMES):
+             payload.write('\r\n'.join([
+                 '--' + client.BOUNDARY,
+                 'Content-Disposition: form-data; name="file%s"; filename="%s"' % (i, name),
+@@ -240,7 +241,7 @@ class FileUploadTests(TestCase):
+         response = self.client.request(**r)
+         # The filenames should have been sanitized by the time it got to the view.
+         received = response.json()
+-        for i, name in enumerate(scary_file_names):
++        for i, name in enumerate(CANDIDATE_TRAVERSAL_FILE_NAMES):
+             got = received["file%s" % i]
+             self.assertEqual(got, "hax0rd.txt")
+ 
+@@ -518,6 +519,36 @@ class FileUploadTests(TestCase):
+         # shouldn't differ.
+         self.assertEqual(os.path.basename(obj.testfile.path), 'MiXeD_cAsE.txt')
+ 
++    def test_filename_traversal_upload(self):
++        os.makedirs(UPLOAD_TO, exist_ok=True)
++        self.addCleanup(shutil.rmtree, MEDIA_ROOT)
++        file_name = '..&#x2F;test.txt',
++        payload = client.FakePayload()
++        payload.write(
++            '\r\n'.join([
++                '--' + client.BOUNDARY,
++                'Content-Disposition: form-data; name="my_file"; '
++                'filename="%s";' % file_name,
++                'Content-Type: text/plain',
++                '',
++                'file contents.\r\n',
++                '\r\n--' + client.BOUNDARY + '--\r\n',
++            ]),
++        )
++        r = {
++            'CONTENT_LENGTH': len(payload),
++            'CONTENT_TYPE': client.MULTIPART_CONTENT,
++            'PATH_INFO': '/upload_traversal/',
++            'REQUEST_METHOD': 'POST',
++            'wsgi.input': payload,
++        }
++        response = self.client.request(**r)
++        result = response.json()
++        self.assertEqual(response.status_code, 200)
++        self.assertEqual(result['file_name'], 'test.txt')
++        self.assertIs(os.path.exists(os.path.join(MEDIA_ROOT, 'test.txt')), False)
++        self.assertIs(os.path.exists(os.path.join(UPLOAD_TO, 'test.txt')), True)
++
+ 
+ @override_settings(MEDIA_ROOT=MEDIA_ROOT)
+ class DirectoryCreationTests(SimpleTestCase):
+@@ -591,6 +622,15 @@ class MultiParserTests(SimpleTestCase):
+         }, StringIO('x'), [], 'utf-8')
+         self.assertEqual(multipart_parser._content_length, 0)
+ 
++    def test_sanitize_file_name(self):
++        parser = MultiPartParser({
++            'CONTENT_TYPE': 'multipart/form-data; boundary=_foo',
++            'CONTENT_LENGTH': '1'
++        }, StringIO('x'), [], 'utf-8')
++        for file_name in CANDIDATE_TRAVERSAL_FILE_NAMES:
++            with self.subTest(file_name=file_name):
++                self.assertEqual(parser.sanitize_file_name(file_name), 'hax0rd.txt')
++
+     def test_rfc2231_parsing(self):
+         test_data = (
+             (b"Content-Type: application/x-stuff; title*=us-ascii'en-us'This%20is%20%2A%2A%2Afun%2A%2A%2A",
+diff --git a/tests/file_uploads/uploadhandler.py b/tests/file_uploads/uploadhandler.py
+index 7c6199f..65d70c6 100644
+--- a/tests/file_uploads/uploadhandler.py
++++ b/tests/file_uploads/uploadhandler.py
+@@ -1,6 +1,8 @@
+ """
+ Upload handlers to test the upload API.
+ """
++import os
++from tempfile import NamedTemporaryFile
+ 
+ from django.core.files.uploadhandler import FileUploadHandler, StopUpload
+ 
+@@ -35,3 +37,32 @@ class ErroringUploadHandler(FileUploadHandler):
+     """A handler that raises an exception."""
+     def receive_data_chunk(self, raw_data, start):
+         raise CustomUploadError("Oops!")
++
++
++class TraversalUploadHandler(FileUploadHandler):
++    """A handler with potential directory-traversal vulnerability."""
++    def __init__(self, request=None):
++        from .views import UPLOAD_TO
++
++        super().__init__(request)
++        self.upload_dir = UPLOAD_TO
++
++    def file_complete(self, file_size):
++        self.file.seek(0)
++        self.file.size = file_size
++        with open(os.path.join(self.upload_dir, self.file_name), 'wb') as fp:
++            fp.write(self.file.read())
++        return self.file
++
++    def new_file(
++        self, field_name, file_name, content_type, content_length, charset=None,
++        content_type_extra=None,
++    ):
++        super().new_file(
++            file_name, file_name, content_length, content_length, charset,
++            content_type_extra,
++        )
++        self.file = NamedTemporaryFile(suffix='.upload', dir=self.upload_dir)
++
++    def receive_data_chunk(self, raw_data, start):
++        self.file.write(raw_data)
+diff --git a/tests/file_uploads/urls.py b/tests/file_uploads/urls.py
+index 3e7985d..eaac1da 100644
+--- a/tests/file_uploads/urls.py
++++ b/tests/file_uploads/urls.py
+@@ -4,6 +4,7 @@ from . import views
+ 
+ urlpatterns = [
+     path('upload/', views.file_upload_view),
++    path('upload_traversal/', views.file_upload_traversal_view),
+     path('verify/', views.file_upload_view_verify),
+     path('unicode_name/', views.file_upload_unicode_name),
+     path('echo/', views.file_upload_echo),
+diff --git a/tests/file_uploads/views.py b/tests/file_uploads/views.py
+index d4947e4..137c6f3 100644
+--- a/tests/file_uploads/views.py
++++ b/tests/file_uploads/views.py
+@@ -6,7 +6,9 @@ from django.http import HttpResponse, HttpResponseServerError, JsonResponse
+ 
+ from .models import FileModel
+ from .tests import UNICODE_FILENAME, UPLOAD_TO
+-from .uploadhandler import ErroringUploadHandler, QuotaUploadHandler
++from .uploadhandler import (
++    ErroringUploadHandler, QuotaUploadHandler, TraversalUploadHandler,
++)
+ 
+ 
+ def file_upload_view(request):
+@@ -158,3 +160,11 @@ def file_upload_fd_closing(request, access):
+     if access == 't':
+         request.FILES  # Trigger file parsing.
+     return HttpResponse('')
++
++
++def file_upload_traversal_view(request):
++    request.upload_handlers.insert(0, TraversalUploadHandler())
++    request.FILES  # Trigger file parsing.
++    return JsonResponse(
++        {'file_name': request.upload_handlers[0].file_name},
++    )
+-- 
+2.17.1
+
diff --git a/meta-python/recipes-devtools/python/python3-django_2.2.16.bb b/meta-python/recipes-devtools/python/python3-django_2.2.16.bb
index 0715abbd4c..eb626e8d3f 100644
--- a/meta-python/recipes-devtools/python/python3-django_2.2.16.bb
+++ b/meta-python/recipes-devtools/python/python3-django_2.2.16.bb
@@ -7,3 +7,5 @@ SRC_URI[sha256sum] = "62cf45e5ee425c52e411c0742e641a6588b7e8af0d2c274a27940931b2
 RDEPENDS_${PN} += "\
     ${PYTHON_PN}-sqlparse \
 "
+SRC_URI += "file://CVE-2021-28658.patch \
+"