Skip to content

Harden XML parsing with secure lxml parser configuration #171

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
ssaurabhkumarsinha38sks-art wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Harden XML parsing with secure lxml parser configuration #171

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 11 additions & 3 deletions authorizenet/apicontrollersbase.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@
import sys
import xml.dom.minidom
import requests
from lxml import objectify
from lxml import etree, objectify

from authorizenet.constants import constants
from authorizenet import apicontractsv1
Expand Down Expand Up @@ -142,21 +142,29 @@ def execute(self):
self._httpResponse.encoding = constants.response_encoding
self._httpResponse = self._httpResponse.text[3:] #strip BOM
self.afterexecute()

# Create secure XML parser to prevent XXE attacks
secure_parser = etree.XMLParser(
resolve_entities=False,
no_network=True,
dtd_validation=False,
load_dtd=False
)
try:
self._response = apicontractsv1.CreateFromDocument(self._httpResponse)
#objectify code
xmlResponse= self._response.toxml(encoding=constants.xml_encoding, element_name=self.getrequesttype())
xmlResponse = xmlResponse.replace(constants.nsNamespace1, b'')
xmlResponse = xmlResponse.replace(constants.nsNamespace2, b'')
self._mainObject = objectify.fromstring(xmlResponse)
self._mainObject = objectify.fromstring(xmlResponse, parser=secure_parser)

except Exception as objectifyexception:
anetLogger.error( 'Create Document Exception: %s, %s', type(objectifyexception), objectifyexception.args )
responseString = self._httpResponse

# removing encoding attribute as objectify fails if it is present
responseString = responseString.replace('encoding=\"utf-8\"', '')
self._mainObject = objectify.fromstring(responseString)
self._mainObject = objectify.fromstring(responseString, parser=secure_parser)
else:
if type(self.getresponseclass()) != type(self._mainObject):
if self._response.messages.resultCode == "Error":
Expand Down