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cloud-init/backport-CVE-2023-1786.patch
sxt1001 d666a0f079 fix CVE-2023-178
2023-05-24 00:19:05 +08:00

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From a378b7e4f47375458651c0972e7cd813f6fe0a6b Mon Sep 17 00:00:00 2001
From: James Falcon <james.falcon@canonical.com>
Date: Wed, 26 Apr 2023 15:11:55 -0500
Subject: [PATCH] Make user/vendor data sensitive and remove log permissions
(#2144)
Because user data and vendor data may contain sensitive information,
this commit ensures that any user data or vendor data written to
instance-data.json gets redacted and is only available to root user.
Also, modify the permissions of cloud-init.log to be 640, so that
sensitive data leaked to the log isn't world readable.
Additionally, remove the logging of user data and vendor data to
cloud-init.log from the Vultr datasource.
LP: #2013967
CVE: CVE-2023-1786
---
cloudinit/sources/DataSourceLXD.py | 11 +++++-
cloudinit/sources/DataSourceVultr.py | 14 +++----
cloudinit/sources/__init__.py | 35 ++++++++++++++---
cloudinit/sources/tests/test_init.py | 58 ++++++++++++++++++++++++----
cloudinit/stages.py | 4 +-
cloudinit/tests/test_stages.py | 18 +++++----
6 files changed, 109 insertions(+), 31 deletions(-)
diff --git a/cloudinit/sources/DataSourceLXD.py b/cloudinit/sources/DataSourceLXD.py
index 732b32f..1e1e9e2 100644
--- a/cloudinit/sources/DataSourceLXD.py
+++ b/cloudinit/sources/DataSourceLXD.py
@@ -14,6 +14,7 @@ import os
import requests
from requests.adapters import HTTPAdapter
+from typing import Tuple
# pylint fails to import the two modules below.
# These are imported via requests.packages rather than urllib3 because:
@@ -173,8 +174,14 @@ class DataSourceLXD(sources.DataSource):
_network_config = sources.UNSET
_crawled_metadata = sources.UNSET
- sensitive_metadata_keys = (
- 'merged_cfg', 'user.meta-data', 'user.vendor-data', 'user.user-data',
+ sensitive_metadata_keys: Tuple[
+ str, ...
+ ] = sources.DataSource.sensitive_metadata_keys + (
+ "user.meta-data",
+ "user.vendor-data",
+ "user.user-data",
+ "cloud-init.user-data",
+ "cloud-init.vendor-data",
)
def _is_platform_viable(self) -> bool:
diff --git a/cloudinit/sources/DataSourceVultr.py b/cloudinit/sources/DataSourceVultr.py
index 68e1ff0..4d41d4e 100644
--- a/cloudinit/sources/DataSourceVultr.py
+++ b/cloudinit/sources/DataSourceVultr.py
@@ -10,6 +10,8 @@ from cloudinit import sources
from cloudinit import util
from cloudinit import version
+from typing import Tuple
+
import cloudinit.sources.helpers.vultr as vultr
LOG = log.getLogger(__name__)
@@ -29,6 +31,10 @@ class DataSourceVultr(sources.DataSource):
dsname = 'Vultr'
+ sensitive_metadata_keys: Tuple[
+ str, ...
+ ] = sources.DataSource.sensitive_metadata_keys + ("startup-script",)
+
def __init__(self, sys_cfg, distro, paths):
super(DataSourceVultr, self).__init__(sys_cfg, distro, paths)
self.ds_cfg = util.mergemanydict([
@@ -54,13 +60,8 @@ class DataSourceVultr(sources.DataSource):
self.get_datasource_data(self.metadata)
# Dump some data so diagnosing failures is manageable
- LOG.debug("Vultr Vendor Config:")
- LOG.debug(util.json_dumps(self.metadata['vendor-data']))
LOG.debug("SUBID: %s", self.metadata['instance-id'])
LOG.debug("Hostname: %s", self.metadata['local-hostname'])
- if self.userdata_raw is not None:
- LOG.debug("User-Data:")
- LOG.debug(self.userdata_raw)
return True
@@ -141,7 +142,4 @@ if __name__ == "__main__":
config = md['vendor-data']
sysinfo = vultr.get_sysinfo()
- print(util.json_dumps(sysinfo))
- print(util.json_dumps(config))
-
# vi: ts=4 expandtab
diff --git a/cloudinit/sources/__init__.py b/cloudinit/sources/__init__.py
index f2f2343..20cc397 100644
--- a/cloudinit/sources/__init__.py
+++ b/cloudinit/sources/__init__.py
@@ -13,7 +13,7 @@ import copy
import json
import os
from collections import namedtuple
-from typing import Dict, List # noqa: F401
+from typing import Dict, List, Tuple # noqa: F401
from cloudinit import dmi
from cloudinit import importer
@@ -103,7 +103,10 @@ def process_instance_metadata(metadata, key_path='', sensitive_keys=()):
sub_key_path = key_path + '/' + key
else:
sub_key_path = key
- if key in sensitive_keys or sub_key_path in sensitive_keys:
+ if (
+ key.lower() in sensitive_keys
+ or sub_key_path.lower() in sensitive_keys
+ ):
sens_keys.append(sub_key_path)
if isinstance(val, str) and val.startswith('ci-b64:'):
base64_encoded_keys.append(sub_key_path)
@@ -124,6 +127,12 @@ def redact_sensitive_keys(metadata, redact_value=REDACT_SENSITIVE_VALUE):
Replace any keys values listed in 'sensitive_keys' with redact_value.
"""
+ # While 'sensitive_keys' should already sanitized to only include what
+ # is in metadata, it is possible keys will overlap. For example, if
+ # "merged_cfg" and "merged_cfg/ds/userdata" both match, it's possible that
+ # "merged_cfg" will get replaced first, meaning "merged_cfg/ds/userdata"
+ # no longer represents a valid key.
+ # Thus, we still need to do membership checks in this function.
if not metadata.get('sensitive_keys', []):
return metadata
md_copy = copy.deepcopy(metadata)
@@ -131,9 +140,14 @@ def redact_sensitive_keys(metadata, redact_value=REDACT_SENSITIVE_VALUE):
path_parts = key_path.split('/')
obj = md_copy
for path in path_parts:
- if isinstance(obj[path], dict) and path != path_parts[-1]:
+ if (
+ path in obj
+ and isinstance(obj[path], dict)
+ and path != path_parts[-1]
+ ):
obj = obj[path]
- obj[path] = redact_value
+ if path in obj:
+ obj[path] = redact_value
return md_copy
@@ -215,7 +229,18 @@ class DataSource(CloudInitPickleMixin, metaclass=abc.ABCMeta):
# N-tuple of keypaths or keynames redact from instance-data.json for
# non-root users
- sensitive_metadata_keys = ('merged_cfg', 'security-credentials',)
+ sensitive_metadata_keys: Tuple[str, ...] = (
+ "merged_cfg",
+ "security-credentials",
+ "userdata",
+ "user-data",
+ "user_data",
+ "vendordata",
+ "vendor-data",
+ # Provide ds/vendor_data to avoid redacting top-level
+ # "vendor_data": {enabled: True}
+ "ds/vendor_data",
+ )
_ci_pkl_version = 1
diff --git a/cloudinit/sources/tests/test_init.py b/cloudinit/sources/tests/test_init.py
index ae09cb1..bce2ab5 100644
--- a/cloudinit/sources/tests/test_init.py
+++ b/cloudinit/sources/tests/test_init.py
@@ -353,11 +353,32 @@ class TestDataSource(CiTestCase):
'availability_zone': 'myaz',
'local-hostname': 'test-subclass-hostname',
'region': 'myregion',
- 'some': {'security-credentials': {
- 'cred1': 'sekret', 'cred2': 'othersekret'}}})
+ 'some': {
+ 'security-credentials': {
+ 'cred1': 'sekret', 'cred2': 'othersekret'
+ }
+ },
+ "someother": {
+ "nested": {
+ "userData": "HIDE ME",
+ }
+ },
+ "VENDOR-DAta": "HIDE ME TOO",
+ },
+ )
self.assertCountEqual(
- ('merged_cfg', 'security-credentials',),
- datasource.sensitive_metadata_keys)
+ (
+ "merged_cfg",
+ "security-credentials",
+ "userdata",
+ "user-data",
+ "user_data",
+ "vendordata",
+ "vendor-data",
+ "ds/vendor_data",
+ ),
+ datasource.sensitive_metadata_keys,
+ )
sys_info = {
"python": "3.7",
"platform":
@@ -373,7 +394,11 @@ class TestDataSource(CiTestCase):
'base64_encoded_keys': [],
'merged_cfg': REDACT_SENSITIVE_VALUE,
'sensitive_keys': [
- 'ds/meta_data/some/security-credentials', 'merged_cfg'],
+ "ds/meta_data/VENDOR-DAta",
+ "ds/meta_data/some/security-credentials",
+ "ds/meta_data/someother/nested/userData",
+ "merged_cfg",
+ ],
'sys_info': sys_info,
'v1': {
'_beta_keys': ['subplatform'],
@@ -381,6 +406,7 @@ class TestDataSource(CiTestCase):
'availability_zone': 'myaz',
'cloud-name': 'subclasscloudname',
'cloud_name': 'subclasscloudname',
+ "cloud_id": "subclasscloudname",
'distro': 'ubuntu',
'distro_release': 'focal',
'distro_version': '20.04',
@@ -401,10 +427,16 @@ class TestDataSource(CiTestCase):
'ds': {
'_doc': EXPERIMENTAL_TEXT,
'meta_data': {
+ "VENDOR-DAta": REDACT_SENSITIVE_VALUE,
'availability_zone': 'myaz',
'local-hostname': 'test-subclass-hostname',
'region': 'myregion',
- 'some': {'security-credentials': REDACT_SENSITIVE_VALUE}}}
+ 'some': {'security-credentials': REDACT_SENSITIVE_VALUE},
+ "someother": {
+ "nested": {"userData": REDACT_SENSITIVE_VALUE}
+ },
+ },
+ },
}
self.assertCountEqual(expected, redacted)
file_stat = os.stat(json_file)
@@ -432,8 +464,18 @@ class TestDataSource(CiTestCase):
"variant": "ubuntu", "dist": ["ubuntu", "20.04", "focal"]}
self.assertCountEqual(
- ('merged_cfg', 'security-credentials',),
- datasource.sensitive_metadata_keys)
+ (
+ "merged_cfg",
+ "security-credentials",
+ "userdata",
+ "user-data",
+ "user_data",
+ "vendordata",
+ "vendor-data",
+ "ds/vendor_data",
+ ),
+ datasource.sensitive_metadata_keys,
+ )
with mock.patch("cloudinit.util.system_info", return_value=sys_info):
datasource.get_data()
sensitive_json_file = self.tmp_path(INSTANCE_JSON_SENSITIVE_FILE, tmp)
diff --git a/cloudinit/stages.py b/cloudinit/stages.py
index 731b298..59b0925 100644
--- a/cloudinit/stages.py
+++ b/cloudinit/stages.py
@@ -204,7 +204,9 @@ class Init(object):
util.ensure_dirs(self._initial_subdirs())
log_file = util.get_cfg_option_str(self.cfg, 'def_log_file')
if log_file:
- util.ensure_file(log_file, mode=0o640, preserve_mode=True)
+ # At this point the log file should have already been created
+ # in the setupLogging function of log.py
+ util.ensure_file(log_file, mode=0o640, preserve_mode=False)
perms = self.cfg.get('syslog_fix_perms')
if not perms:
perms = {}
diff --git a/cloudinit/tests/test_stages.py b/cloudinit/tests/test_stages.py
index a50836a..aeab17a 100644
--- a/cloudinit/tests/test_stages.py
+++ b/cloudinit/tests/test_stages.py
@@ -458,21 +458,25 @@ class TestInit_InitializeFilesystem:
# Assert we create it 0o640 by default if it doesn't already exist
assert 0o640 == stat.S_IMODE(log_file.stat().mode)
- def test_existing_file_permissions_are_not_modified(self, init, tmpdir):
- """If the log file already exists, we should not modify its permissions
+ def test_existing_file_permissions(self, init, tmpdir):
+ """Test file permissions are set as expected.
+
+ CIS Hardening requires 640 permissions. These permissions are
+ currently hardcoded on every boot, but if there's ever a reason
+ to change this, we need to then ensure that they
+ are *not* set every boot.
See https://bugs.launchpad.net/cloud-init/+bug/1900837.
"""
- # Use a mode that will never be made the default so this test will
- # always be valid
- mode = 0o606
log_file = tmpdir.join("cloud-init.log")
log_file.ensure()
- log_file.chmod(mode)
+ # Use a mode that will never be made the default so this test will
+ # always be valid
+ log_file.chmod(0o606)
init._cfg = {"def_log_file": str(log_file)}
init._initialize_filesystem()
- assert mode == stat.S_IMODE(log_file.stat().mode)
+ assert 0o640 == stat.S_IMODE(log_file.stat().mode)
# vi: ts=4 expandtab
--
2.33.0
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