Attachment 696367 Details for Bug 910224 – nova-essex-CVE-2013-0280.patch

[patch] nova-essex-CVE-2013-0280.patch

nova-essex-CVE-2013-0280.patch (text/plain), 11.40 KB, created by Kurt Seifried on 2013-02-12 04:01:16 UTC

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Creator: Kurt Seifried

Created: 2013-02-12 04:01:16 UTC

Size: 11.40 KB

patch

obsolete

>From 53c38ca4e76b75ffc4b9a48c807298c74dab69cd Mon Sep 17 00:00:00 2001
>From: Dan Prince <dprince@redhat.com>
>Date: Sat, 2 Feb 2013 14:32:12 -0500
>Subject: [PATCH] Add a safe_minidom_parse_string function.
>
>Adds a new utils.safe_minidom_parse_string function and
>updates external API facing Nova modules to use it.
>This ensures we have safe defaults on our incoming API XML parsing.
>
>Internally safe_minidom_parse_string uses a ProtectedExpatParser
>class to disable DTDs and entities from being parsed when using
>minidom.
>
>Fixes LP Bug #1100282 for Essex.
>
>Change-Id: I815b27ff2845293e3d6771ff8f99944ec08ccbd5
>---
> nova/api/openstack/common.py                       | 10 ++---
> nova/api/openstack/compute/contrib/hosts.py        |  4 +-
> .../openstack/compute/contrib/security_groups.py   |  5 +--
> nova/api/openstack/compute/servers.py              |  5 +--
> nova/api/openstack/wsgi.py                         | 12 +++---
> nova/tests/test_utils.py                           | 35 +++++++++++++++++
> nova/utils.py                                      | 44 ++++++++++++++++++++++
> 7 files changed, 96 insertions(+), 19 deletions(-)
>
>diff --git a/nova/api/openstack/common.py b/nova/api/openstack/common.py
>index 8e3daaa..87eccc5 100644
>--- a/nova/api/openstack/common.py
>+++ b/nova/api/openstack/common.py
>@@ -21,7 +21,6 @@ import re
> import urlparse
> 
> import webob
>-from xml.dom import minidom
> 
> from nova.api.openstack import wsgi
> from nova.api.openstack import xmlutil
>@@ -31,6 +30,7 @@ from nova.compute import utils as compute_utils
> from nova import flags
> from nova import log as logging
> from nova import quota
>+from nova import utils
> 
> 
> LOG = logging.getLogger(__name__)
>@@ -338,7 +338,7 @@ def raise_http_conflict_for_instance_invalid_state(exc, action):
> 
> class MetadataDeserializer(wsgi.MetadataXMLDeserializer):
>     def deserialize(self, text):
>-        dom = minidom.parseString(text)
>+        dom = utils.safe_minidom_parse_string(text)
>         metadata_node = self.find_first_child_named(dom, "metadata")
>         metadata = self.extract_metadata(metadata_node)
>         return {'body': {'metadata': metadata}}
>@@ -346,7 +346,7 @@ class MetadataDeserializer(wsgi.MetadataXMLDeserializer):
> 
> class MetaItemDeserializer(wsgi.MetadataXMLDeserializer):
>     def deserialize(self, text):
>-        dom = minidom.parseString(text)
>+        dom = utils.safe_minidom_parse_string(text)
>         metadata_item = self.extract_metadata(dom)
>         return {'body': {'meta': metadata_item}}
> 
>@@ -364,7 +364,7 @@ class MetadataXMLDeserializer(wsgi.XMLDeserializer):
>         return metadata
> 
>     def _extract_metadata_container(self, datastring):
>-        dom = minidom.parseString(datastring)
>+        dom = utils.safe_minidom_parse_string(datastring)
>         metadata_node = self.find_first_child_named(dom, "metadata")
>         metadata = self.extract_metadata(metadata_node)
>         return {'body': {'metadata': metadata}}
>@@ -376,7 +376,7 @@ class MetadataXMLDeserializer(wsgi.XMLDeserializer):
>         return self._extract_metadata_container(datastring)
> 
>     def update(self, datastring):
>-        dom = minidom.parseString(datastring)
>+        dom = utils.safe_minidom_parse_string(datastring)
>         metadata_item = self.extract_metadata(dom)
>         return {'body': {'meta': metadata_item}}
> 
>diff --git a/nova/api/openstack/compute/contrib/hosts.py b/nova/api/openstack/compute/contrib/hosts.py
>index 202c8ca..2918733 100644
>--- a/nova/api/openstack/compute/contrib/hosts.py
>+++ b/nova/api/openstack/compute/contrib/hosts.py
>@@ -16,7 +16,6 @@
> """The hosts admin extension."""
> 
> import webob.exc
>-from xml.dom import minidom
> from xml.parsers import expat
> 
> from nova.api.openstack import wsgi
>@@ -27,6 +26,7 @@ from nova import db
> from nova import exception
> from nova import flags
> from nova import log as logging
>+from nova import utils
> 
> 
> LOG = logging.getLogger(__name__)
>@@ -80,7 +80,7 @@ class HostShowTemplate(xmlutil.TemplateBuilder):
> class HostDeserializer(wsgi.XMLDeserializer):
>     def default(self, string):
>         try:
>-            node = minidom.parseString(string)
>+            node = utils.safe_minidom_parse_string(string)
>         except expat.ExpatError:
>             msg = _("cannot understand XML")
>             raise exception.MalformedRequestBody(reason=msg)
>diff --git a/nova/api/openstack/compute/contrib/security_groups.py b/nova/api/openstack/compute/contrib/security_groups.py
>index a9368c5..4078c54 100644
>--- a/nova/api/openstack/compute/contrib/security_groups.py
>+++ b/nova/api/openstack/compute/contrib/security_groups.py
>@@ -17,7 +17,6 @@
> """The security groups extension."""
> 
> import urllib
>-from xml.dom import minidom
> 
> from webob import exc
> import webob
>@@ -112,7 +111,7 @@ class SecurityGroupXMLDeserializer(wsgi.MetadataXMLDeserializer):
>     """
>     def default(self, string):
>         """Deserialize an xml-formatted security group create request"""
>-        dom = minidom.parseString(string)
>+        dom = utils.safe_minidom_parse_string(string)
>         security_group = {}
>         sg_node = self.find_first_child_named(dom,
>                                                'security_group')
>@@ -133,7 +132,7 @@ class SecurityGroupRulesXMLDeserializer(wsgi.MetadataXMLDeserializer):
> 
>     def default(self, string):
>         """Deserialize an xml-formatted security group create request"""
>-        dom = minidom.parseString(string)
>+        dom = utils.safe_minidom_parse_string(string)
>         security_group_rule = self._extract_security_group_rule(dom)
>         return {'body': {'security_group_rule': security_group_rule}}
> 
>diff --git a/nova/api/openstack/compute/servers.py b/nova/api/openstack/compute/servers.py
>index f23a2a3..49f3cec 100644
>--- a/nova/api/openstack/compute/servers.py
>+++ b/nova/api/openstack/compute/servers.py
>@@ -17,7 +17,6 @@
> import base64
> import os
> import socket
>-from xml.dom import minidom
> 
> from webob import exc
> import webob
>@@ -240,7 +239,7 @@ class ActionDeserializer(CommonDeserializer):
>     """
> 
>     def default(self, string):
>-        dom = minidom.parseString(string)
>+        dom = utils.safe_minidom_parse_string(string)
>         action_node = dom.childNodes[0]
>         action_name = action_node.tagName
> 
>@@ -336,7 +335,7 @@ class CreateDeserializer(CommonDeserializer):
> 
>     def default(self, string):
>         """Deserialize an xml-formatted server create request"""
>-        dom = minidom.parseString(string)
>+        dom = utils.safe_minidom_parse_string(string)
>         server = self._extract_server(dom)
>         return {'body': {'server': server}}
> 
>diff --git a/nova/api/openstack/wsgi.py b/nova/api/openstack/wsgi.py
>index f654252..3ec9e36 100644
>--- a/nova/api/openstack/wsgi.py
>+++ b/nova/api/openstack/wsgi.py
>@@ -153,7 +153,7 @@ class XMLDeserializer(TextDeserializer):
>         plurals = set(self.metadata.get('plurals', {}))
> 
>         try:
>-            node = minidom.parseString(datastring).childNodes[0]
>+            node = utils.safe_minidom_parse_string(datastring).childNodes[0]
>             return {node.nodeName: self._from_xml_node(node, plurals)}
>         except expat.ExpatError:
>             msg = _("cannot understand XML")
>@@ -195,11 +195,11 @@ class XMLDeserializer(TextDeserializer):
> 
>     def extract_text(self, node):
>         """Get the text field contained by the given node"""
>-        if len(node.childNodes) == 1:
>-            child = node.childNodes[0]
>+        ret_val = ""
>+        for child in node.childNodes:
>             if child.nodeType == child.TEXT_NODE:
>-                return child.nodeValue
>-        return ""
>+                ret_val += child.nodeValue
>+        return ret_val
> 
>     def find_attribute_or_element(self, parent, name):
>         """Get an attribute value; fallback to an element if not found"""
>@@ -550,7 +550,7 @@ def action_peek_json(body):
> def action_peek_xml(body):
>     """Determine action to invoke."""
> 
>-    dom = minidom.parseString(body)
>+    dom = utils.safe_minidom_parse_string(body)
>     action_node = dom.childNodes[0]
> 
>     return action_node.tagName
>diff --git a/nova/tests/test_utils.py b/nova/tests/test_utils.py
>index 5babf4c..3d2bdd2 100644
>--- a/nova/tests/test_utils.py
>+++ b/nova/tests/test_utils.py
>@@ -718,6 +718,41 @@ class DeprecationTest(test.TestCase):
>         result = utils.service_is_up(service)
>         self.assertFalse(result)
> 
>+
>+    def test_safe_parse_xml(self):
>+
>+        normal_body = ("""
>+                 <?xml version="1.0" ?><foo>
>+                    <bar>
>+                        <v1>hey</v1>
>+                        <v2>there</v2>
>+                    </bar>
>+                </foo>""").strip()
>+
>+        def killer_body():
>+            return (("""<!DOCTYPE x [
>+                    <!ENTITY a "%(a)s">
>+                    <!ENTITY b "%(b)s">
>+                    <!ENTITY c "%(c)s">]>
>+                <foo>
>+                    <bar>
>+                        <v1>%(d)s</v1>
>+                    </bar>
>+                </foo>""") % {
>+                'a': 'A' * 10,
>+                'b': '&a;' * 10,
>+                'c': '&b;' * 10,
>+                'd': '&c;' * 9999,
>+            }).strip()
>+
>+        dom = utils.safe_minidom_parse_string(normal_body)
>+        self.assertEqual(normal_body, str(dom.toxml()))
>+
>+        self.assertRaises(ValueError,
>+                          utils.safe_minidom_parse_string,
>+                          killer_body())
>+
>+
>     def test_xhtml_escape(self):
>         self.assertEqual('&quot;foo&quot;', utils.xhtml_escape('"foo"'))
>         self.assertEqual('&apos;foo&apos;', utils.xhtml_escape("'foo'"))
>diff --git a/nova/utils.py b/nova/utils.py
>index 6535b06..306740f 100644
>--- a/nova/utils.py
>+++ b/nova/utils.py
>@@ -42,6 +42,10 @@ import time
> import types
> import uuid
> import warnings
>+from xml.dom import minidom
>+from xml.parsers import expat
>+from xml import sax
>+from xml.sax import expatreader
> from xml.sax import saxutils
> 
> from eventlet import corolocal
>@@ -723,6 +727,46 @@ class LoopingCall(object):
>         return self.done.wait()
> 
> 
>+class ProtectedExpatParser(expatreader.ExpatParser):
>+    """An expat parser which disables DTD's and entities by default."""
>+
>+    def __init__(self, forbid_dtd=True, forbid_entities=True,
>+                 *args, **kwargs):
>+        # Python 2.x old style class
>+        expatreader.ExpatParser.__init__(self, *args, **kwargs)
>+        self.forbid_dtd = forbid_dtd
>+        self.forbid_entities = forbid_entities
>+
>+    def start_doctype_decl(self, name, sysid, pubid, has_internal_subset):
>+        raise ValueError("Inline DTD forbidden")
>+
>+    def entity_decl(self, entityName, is_parameter_entity, value, base,
>+                    systemId, publicId, notationName):
>+        raise ValueError("<!ENTITY> forbidden")
>+
>+    def unparsed_entity_decl(self, name, base, sysid, pubid, notation_name):
>+        # expat 1.2
>+        raise ValueError("<!ENTITY> forbidden")
>+
>+    def reset(self):
>+        expatreader.ExpatParser.reset(self)
>+        if self.forbid_dtd:
>+            self._parser.StartDoctypeDeclHandler = self.start_doctype_decl
>+        if self.forbid_entities:
>+            self._parser.EntityDeclHandler = self.entity_decl
>+            self._parser.UnparsedEntityDeclHandler = self.unparsed_entity_decl
>+
>+
>+def safe_minidom_parse_string(xml_string):
>+    """Parse an XML string using minidom safely.
>+
>+    """
>+    try:
>+        return minidom.parseString(xml_string, parser=ProtectedExpatParser())
>+    except sax.SAXParseException as se:
>+        raise expat.ExpatError()
>+
>+
> def xhtml_escape(value):
>     """Escapes a string so it is valid within XML or XHTML.
> 
>-- 
>1.8.1
>

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Attachments on bug 910224: 696367 | 696368 | 696369