CVE-2021-21360 (published 2021-03-09T01:15Z)

Products.GenericSetup is a mini-framework for expressing the configured state of a Zope Site as a set of filesystem artifacts. In Products.GenericSetup before version 2.1.1 there is an information disclosure vulnerability - anonymous visitors may view log and snapshot files generated by the Generic Setup Tool. The problem has been fixed in version 2.1.1. Depending on how you have installed Products.GenericSetup, you should change the buildout version pin to 2.1.1 and re-run the buildout, or if you used pip simply do pip install `"Products.GenericSetup>=2.1.1"`.

Severity: MEDIUM
CVSS v2 base score: 5.0 (AV:N/AC:L/Au:N/C:P/I:N/A:N)
CVSS v3 base score: 5.3, MEDIUM (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)

Weakness information:
cwe_id: CWE-200
cwe_name: Exposure of Sensitive Information to an Unauthorized Actor
description: The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
extended_description: 
	   There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker.  Some kinds of sensitive information include:
       
         private, personal information, such as personal messages, financial data, health records, geographic location, or contact details
         system status and environment, such as the operating system and installed packages
		 business secrets and intellectual property
		 network status and configuration
		 the product's own code or internal state
         metadata, e.g. logging of connections or message headers
		 indirect information, such as a discrepancy between two internal operations that can be observed by an outsider
       
	    Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected.  These parties include:
               
                  the product's own users
                  people or organizations whose information is created or used by the product, even if they are not direct product users
		  the product's administrators, including the admins of the system(s) and/or networks on which the product operates
                  the developer
               
	    Information exposures can occur in different ways:
               
                  the code explicitly inserts sensitive information into resources or messages that are intentionally made accessible to unauthorized actors, but should not contain the information - i.e., the information should have been "scrubbed" or "sanitized"
                  a different weakness or mistake indirectly inserts the sensitive information into resources, such as a web script error revealing the full system path of the program.
                  the code manages resources that intentionally contain sensitive information, but the resources are unintentionally made accessible to unauthorized actors. In this case, the information exposure is resultant - i.e., a different weakness enabled the access to the information in the first place.
               
	    It is common practice to describe any loss of confidentiality as an "information exposure," but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read.  CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.
         
         

Fix information:
repo_url: https://github.com/zopefoundation/Products.GenericSetup
commit_details: repo_url: https://github.com/zopefoundation/Products.GenericSetup
author: Maurits van Rees
author_date: 2021-03-02 00:43:04+01:00
msg: Enforce access control on snapshot files and folders.
repository: repo_url: https://github.com/zopefoundation/Products.GenericSetup
repo_name: zopefoundation/Products.GenericSetup
description: Mini-framework for expressing the configured state of a Zope Site as a set of filesystem artifacts
repo_language: Python
owner: zopefoundation
file_changes: filename: CHANGES.rst
change_type: ModificationType.MODIFY
diff: @@ -4,7 +4,7 @@ Changelog
 2.1.1 (unreleased)
 ------------------
 
-- Enforce access control on setup tool log files
+- Enforce access control on setup tool log files and snapshot files and folders.
   (`#101 <https://github.com/zopefoundation/Products.GenericSetup/issues/101>`_)
 
 

programming_language: Markdown
filename: context.py
change_type: ModificationType.MODIFY
diff: @@ -26,6 +26,7 @@ from tarfile import TarInfo
 import six
 
 from AccessControl.class_init import InitializeClass
+from AccessControl.Permissions import view
 from AccessControl.SecurityInfo import ClassSecurityInfo
 from Acquisition import Implicit
 from Acquisition import aq_base
@@ -499,6 +500,10 @@ class SnapshotExportContext(BaseContext):
         # MISSING: switch on content_type
         ob = self._createObjectByType(filename, text, content_type)
         folder._setObject(str(filename), ob)  # No Unicode IDs!
+        # Tighten the View permission on the new object.
+        # Only the owner and Manager users may view the log.
+        # file_ob = self._getOb(name)
+        ob.manage_permission(view, ('Manager', 'Owner'), 0)
 
     @security.protected(ManagePortal)
     def getSnapshotURL(self):
@@ -559,8 +564,10 @@ class SnapshotExportContext(BaseContext):
             if element not in current.objectIds():
                 # No Unicode IDs!
                 current._setObject(str(element), Folder(element))
-
-            current = current._getOb(element)
+                current = current._getOb(element)
+                current.manage_permission(view, ('Manager', 'Owner'), 0)
+            else:
+                current = current._getOb(element)
 
         return current
 

programming_language: Python
filename: test_tool.py
change_type: ModificationType.MODIFY
diff: @@ -473,6 +473,15 @@ class SetupToolTests(FilesystemTestBase, TarballTester, ConformsToISetupTool):
         logged = [x for x in tool.objectIds('File') if x.startswith(prefix)]
         self.assertEqual(len(logged), 1)
 
+    def check_restricted_access(self, obj):
+        # For most objects that we create, we do not want ordinary users to
+        # see it, also not when they have View permission on a higher level.
+        rop_info = obj.rolesOfPermission(view)
+        allowed_roles = sorted([x['name'] for x in rop_info
+                                if x['selected']])
+        self.assertEqual(allowed_roles, ['Manager', 'Owner'])
+        self.assertFalse(obj.acquiredRolesAreUsedBy(view))
+
     def test_runAllImportStepsFromProfile_unicode_id_creates_reports(self):
 
         TITLE = 'original title'
@@ -497,11 +506,7 @@ class SetupToolTests(FilesystemTestBase, TarballTester, ConformsToISetupTool):
         logged = [x for x in tool.objectIds('File')]
         for file_id in logged:
             file_ob = tool._getOb(file_id)
-            rop_info = file_ob.rolesOfPermission(view)
-            allowed_roles = sorted([x['name'] for x in rop_info
-                                    if x['selected']])
-            self.assertEqual(allowed_roles, ['Manager', 'Owner'])
-            self.assertFalse(file_ob.acquiredRolesAreUsedBy(view))
+            self.check_restricted_access(file_ob)
 
     def test_runAllImportStepsFromProfile_sorted_explicit_purge(self):
 
@@ -1101,6 +1106,15 @@ class SetupToolTests(FilesystemTestBase, TarballTester, ConformsToISetupTool):
         self.assertEqual(info['id'], 'default')
         self.assertEqual(info['title'], 'default')
 
+        # Check access restriction on snapshot files and folders
+        self.check_restricted_access(tool.snapshots)
+        self.check_restricted_access(snapshot)
+        for obj in snapshot.objectValues():
+            self.check_restricted_access(obj)
+            if hasattr(aq_base(obj), 'objectValues'):
+                for child in obj.objectValues():
+                    self.check_restricted_access(child)
+
     def test_applyContext(self):
         from ..tool import EXPORT_STEPS_XML
         from ..tool import IMPORT_STEPS_XML

programming_language: Python