[BUG] win_lgpo does not account for spaces in XMLNS URLs #66992

willchenmark · 2024-10-23T19:40:39Z

Description
The win_lgpo module used does not currently attempt to escape spaces found in xmlns definitions.

Setup

on-prem machine (Windows 11 24H2)
VM (Virtualbox, KVM, etc. please specify)
VM running on a cloud service, please be explicit and add details
container (Kubernetes, Docker, containerd, etc. please specify)
or a combination, please be explicit
jails if it is FreeBSD
classic packaging
onedir packaging
used bootstrap to install

Steps to Reproduce the behavior
On a fresh Windows 11 24H2 system, attempt to apply any GPO that references the WindowsDefender-D0DE2C.adml definition, such as this user policy.

salt@master:/srv/salt# cat test.sls
"[BACKGROUND] Prevent desktop background from being changed":
  lgpo.set:
    - user_policy:
        Prevent changing desktop background: Enabled

The result will be an invalid URI error from lxml.

salt@master:/srv/salt# salt DEVEL-W-ea96054 state.apply test
DEVEL-W-ea96054:                                                                                                                                       
----------                                                                                                                                             
          ID: [BACKGROUND] Prevent desktop background from being changed                                                                               
    Function: lgpo.set                                                                                                                                 
      Result: False                                                                                                                                    
     Comment: An exception occurred in this state: Traceback (most recent call last):                                                                  
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\modules\win_lgpo.py", line 5143, in _parse_xml                         
                  xml_tree = lxml.etree.parse(out_file, parser=parser)                                                                                 
                File "src\lxml\etree.pyx", line 3538, in lxml.etree.parse                                                                              
                File "src\lxml\parser.pxi", line 1876, in lxml.etree._parseDocument                                                                    
                File "src\lxml\parser.pxi", line 1902, in lxml.etree._parseDocumentFromURL                                                             
                File "src\lxml\parser.pxi", line 1805, in lxml.etree._parseDocFromFile                                                                 
                File "src\lxml\parser.pxi", line 1177, in lxml.etree._BaseParser._parseDocFromFile                                                     
                File "src\lxml\parser.pxi", line 615, in lxml.etree._ParserContext._handleParseResultDoc
                File "src\lxml\parser.pxi", line 725, in lxml.etree._handleParseResult                                        
                File "src\lxml\parser.pxi", line 654, in lxml.etree._raiseParseError
                File "file:/C:/ProgramData/Salt%20Project/Salt/var/cache/salt/minion/lgpo/policy_defs/WindowsDefender-D0DE2CD.adml", line 1
              lxml.etree.XMLSyntaxError: xmlns: 'http://schemas.microsoft.com/GroupPolicy/2006/07/Policysecurity intelligence' is not a valid URI, line
 1, column 246                                                                                                                                         
                                                                                                                                                       
              During handling of the above exception, another exception occurred:                 
                                                                                                                                                       
              Traceback (most recent call last):                                                                                                       
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\state.py", line 2440, in call
                  ret = self.states[cdata["full"]](                                                                                                    
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\loader\lazy.py", line 159, in __call__                                 
                  ret = self.loader.run(run_func, *args, **kwargs)         
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\loader\lazy.py", line 1245, in run                                     
                  return self._last_context.run(self._run_as, _func_or_method, *args, **kwargs)
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\loader\lazy.py", line 1260, in _run_as
                  ret = _func_or_method(*args, **kwargs)                
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\loader\lazy.py", line 1296, in wrapper
                  return f(*args, **kwargs)        
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\states\win_lgpo.py", line 412, in set_
                  lookup = __salt__["lgpo.get_policy_info"](      
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\loader\lazy.py", line 159, in __call__
                  ret = self.loader.run(run_func, *args, **kwargs)                                                                                     
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\loader\lazy.py", line 1245, in run    
                  return self._last_context.run(self._run_as, _func_or_method, *args, **kwargs)
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\loader\lazy.py", line 1260, in _run_as
                  ret = _func_or_method(*args, **kwargs)
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\modules\win_lgpo.py", line 8755, in get_policy_info
                  success, policy_xml_item, policy_name_list, message = _lookup_admin_template(
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\modules\win_lgpo.py", line 8294, in _lookup_admin_template
                  admx_policy_definitions = _get_policy_definitions(language=adml_language)
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\modules\win_lgpo.py", line 5326, in _get_policy_definitions
                  _load_policy_definitions(path=path, language=language)                                                                               
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\modules\win_lgpo.py", line 5300, in _load_policy_definitions
                  xml_tree = _parse_xml(adml_file)      
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\modules\win_lgpo.py", line 5147, in _parse_xml     
                  xml_tree = _remove_unicode_encoding(out_file)
                File "C:\Program Files\Salt Project\Salt\Lib\site-packages\salt\modules\win_lgpo.py", line 5040, in _remove_unicode_encoding
                  r' encoding=[\'"]+unicode[\'"]+', "", xml_content.decode("utf-16"), count=1
              UnicodeDecodeError: 'utf-16-le' codec can't decode byte 0x0a in position 134714: truncated data

That invalid URI error is caused by this adml file in the policy_defs cache:
C:\ProgramData\Salt Project\Salt\var\cache\salt\minion\lgpo\policy_defs\WindowsDefender-D0DE2C.adml

Specifically the Policysecurity intelligence on the first line.
https://github.com/microsoft/mdatp-devicecontrol/blob/main/windows/WindowsDefender.adml#L1

Expected behavior
The state should apply correctly, this would be the expected output.

DEVEL-W-ea96054:
----------
          ID: [BACKGROUND] Prevent desktop background from being changed
    Function: lgpo.set
      Result: True
     Comment: The following policies changed:
              Prevent changing desktop background
     Started: 14:35:35.471570
    Duration: 11736.57 ms
     Changes:   
              ----------
              new:
                  ----------
                  User Configuration:
                      ----------
                      Prevent changing desktop background:
                          Enabled
              old:
                  ----------
                  User Configuration:
                      ----------
                      Prevent changing desktop background:
                          Not Configured

Summary for DEVEL-W-ea96054
------------
Succeeded: 1 (changed=1)
Failed:    0
------------
Total states run:     1
Total run time:  11.737 s

More specifically any spaces that appear in xmlns urls should be escaped with '%20'. Such that
<policyDefinitionResources xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" revision="1.0" schemaVersion="1.0" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/Policysecurity intelligence">
becomes
<policyDefinitionResources xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" revision="1.0" schemaVersion="1.0" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/Policysecurity%20intelligence">

Versions Report

salt --versions-report

This is from the minion, as the issue is specific to the Windows salt-minion.

Salt Version:
          Salt: 3006.9
 
Python Version:
        Python: 3.10.14 (heads/main:9f7d197, Jun 26 2024, 11:42:40) [MSC v.1940 64 bit (AMD64)]
 
Dependency Versions:
          cffi: 1.14.6
      cherrypy: 18.6.1
  cryptography: 42.0.5
      dateutil: 2.8.1
     docker-py: Not Installed
         gitdb: 4.0.7
     gitpython: Not Installed
        Jinja2: 3.1.4
       libgit2: Not Installed
  looseversion: 1.0.2
      M2Crypto: Not Installed
          Mako: Not Installed
       msgpack: 1.0.2
  msgpack-pure: Not Installed
  mysql-python: Not Installed
     packaging: 22.0
     pycparser: 2.21
      pycrypto: Not Installed
  pycryptodome: 3.19.1
        pygit2: Not Installed
  python-gnupg: 0.4.8
        PyYAML: 6.0.1
         PyZMQ: 25.0.2
        relenv: 0.17.0
         smmap: 4.0.0
       timelib: 0.2.4
       Tornado: 4.5.3
           ZMQ: 4.3.4
 
System Versions:
          dist:   
        locale: utf-8
       machine: AMD64
       release: 10
        system: Windows
       version: 10 10.0.26100 SP0 Multiprocessor Free

Additional context

This might not be the best way to handle this, but I was able to correct the error by adding an additional function to modules/win_lgpo.py to escape those spaces, and then added it to the for line iterator in _parse_xml.

--- a/salt/modules/win_lgpo.py	2024-10-22 15:39:57.480400553 -0400
+++ b/salt/modules/win_lgpo.py	2024-10-23 15:29:04.600779526 -0400
@@ -5060,6 +5060,16 @@
     xml_tree = lxml.etree.parse(io.StringIO(modified_xml))
     return xml_tree
 
+def _encode_xmlns_url(match):
+    """
+    Escape spaces in xmlns urls
+    """
+    before_xmlns = match.group(1)
+    xmlns = match.group(2)
+    url = match.group(3)
+    after_url = match.group(4)
+    encoded_url = re.sub(r'\s+', '%20', url)
+    return f'{before_xmlns}{xmlns}="{encoded_url}"{after_url}'
 
 def _parse_xml(adm_file):
     """
@@ -5107,6 +5117,8 @@
                 encoding = "utf-16"
                 raw = raw.decode(encoding)
             for line in raw.split("\r\n"):
+                if 'xmlns="' in line:
+                    line = re.sub(r'(.*)(\bxmlns(?::\w+)?)\s*=\s*"([^"]+)"(.*)', _encode_xmlns_url, line)
                 if 'key="' in line:
                     start = line.index('key="')
                     q1 = line[start:].index('"') + start

The text was updated successfully, but these errors were encountered:

welcome · 2024-10-23T19:40:42Z

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dhs-rec · 2024-11-20T14:18:13Z

Just in case: Also happens on Server 2025, with Salt 3006.7.

bharrison-it · 2024-12-03T21:13:57Z

The patched module per @willchenmark didn't correct the problem during testing - returned output is the same.

willchenmark · 2024-12-03T21:19:10Z

@bharrison-it did you make the change on the minion or the master? Re-reading my issue, I failed to clarify that I made the change on the minion side.

bharrison-it · 2024-12-04T01:15:32Z

@willchenmark specifically I copied win_lgpo.py from /opt/saltstack/salt/lib/python3.10/site-packages/salt/modules (debian location) to /srv/salt/_modules, patched per the comment then synced the modules back to the minion with saltutil.sync_modules.

I confirmed the minion is indeed running the patched module, indicated by the execution path under 'extmods', but the same error occurs during the state run as with the vanilla win_lgpo mod.

      ID: windows_components_microsoft_defender_antivirus_policy
Function: lgpo.set
  Result: False
 Comment: An exception occurred in this state: Traceback (most recent call last):
            File "C:\ProgramData\Salt Project\Salt\var\cache\salt\minion\extmods\modules\win_lgpo.py", line 5143, in _parse_xml
              xml_tree = lxml.etree.parse(out_file, parser=parser)
            File "src\lxml\etree.pyx", line 3538, in lxml.etree.parse
            File "src\lxml\parser.pxi", line 1876, in lxml.etree._parseDocument
            File "src\lxml\parser.pxi", line 1902, in lxml.etree._parseDocumentFromURL
            File "src\lxml\parser.pxi", line 1805, in lxml.etree._parseDocFromFile
            File "src\lxml\parser.pxi", line 1177, in lxml.etree._BaseParser._parseDocFromFile
            File "src\lxml\parser.pxi", line 615, in lxml.etree._ParserContext._handleParseResultDoc
            File "src\lxml\parser.pxi", line 725, in lxml.etree._handleParseResult
            File "src\lxml\parser.pxi", line 654, in lxml.etree._raiseParseError
            File "file:/C:/ProgramData/Salt%20Project/Salt/var/cache/salt/minion/lgpo/policy_defs/WindowsDefender-D0DE2CD.adml", line 1
          lxml.etree.XMLSyntaxError: xmlns: 'http://schemas.microsoft.com/GroupPolicy/2006/07/Policysecurity intelligence' is not a valid URI, line 1, column 246

I did also confirm the copy of win_lgpo.py under extmods on the minion does contain the patched code.

Not sure what's going on as your function appears sound to me.

bharrison-it · 2024-12-04T03:12:46Z

@willchenmark My issue was pushing the patched win_lgpo.py to the minion and calling it without having removed the incorrectly parsed adml files from minion cache first.

For any minions which have run the un-patched module, saltutil.clear_cache (or, i assume, manual deletion of the affected adml file) can be utilized to clear the previously cached contents of the lgpo policy_defs folder and old, incorrectly parsed adml files.

A subsequent run of saltutil.sync_all resynced the patched win_lgpo module, and finally and a state call to lgpo.set prompted the patched win_lgpo module to parse the adml files and completed substitution as expected. State calls to lgpo.set now work as expected.

twangboy · 2025-01-06T19:44:40Z

@willchenmark Would you be able to make a PR for this?

willchenmark · 2025-01-06T19:54:19Z

@twangboy absolutely, happy to do so!

Opened PR #67129

I see that I'll need to add tests to the PR, not positive about docs though. The functionality of lgpo doesn't change materially, so I don't think any additional documentation is needed?

willchenmark added Bug broken, incorrect, or confusing behavior needs-triage labels Oct 23, 2024

twangboy self-assigned this Oct 29, 2024

doesitblend added the VMware label Dec 13, 2024

twangboy removed the needs-triage label Jan 6, 2025

willchenmark linked a pull request Jan 6, 2025 that will close this issue

Escape spaces found while parsing GPO XMLNS tags #67129

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[BUG] win_lgpo does not account for spaces in XMLNS URLs #66992

[BUG] win_lgpo does not account for spaces in XMLNS URLs #66992

willchenmark commented Oct 23, 2024

welcome bot commented Oct 23, 2024

dhs-rec commented Nov 20, 2024

bharrison-it commented Dec 3, 2024

willchenmark commented Dec 3, 2024

bharrison-it commented Dec 4, 2024

bharrison-it commented Dec 4, 2024

twangboy commented Jan 6, 2025

willchenmark commented Jan 6, 2025 •

edited

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[BUG] win_lgpo does not account for spaces in XMLNS URLs #66992

[BUG] win_lgpo does not account for spaces in XMLNS URLs #66992

Comments

willchenmark commented Oct 23, 2024

welcome bot commented Oct 23, 2024

dhs-rec commented Nov 20, 2024

bharrison-it commented Dec 3, 2024

willchenmark commented Dec 3, 2024

bharrison-it commented Dec 4, 2024

bharrison-it commented Dec 4, 2024

twangboy commented Jan 6, 2025

willchenmark commented Jan 6, 2025 • edited Loading

willchenmark commented Jan 6, 2025 •

edited

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