XML injections in Python using xml.dom.minidom

Question

I scanned Python source code using AppScan and it says that the code contains potential vulnerabilities (XML Injection). For example:

import xml.dom.minidom

...
dom = xml.dom.minidom.parse(filename)
...
document = xml.dom.minidom.parseString(xmlStr)
...

I installed the defusedxml and replaced all parsings where use the standard Python xml package with parse/parseString from defusedxml.minidom & defusedxml.cElementTree:

import defusedxml.minidom

...
dom = defusedxml.minidom.parse(filename)
...
document = defusedxml.minidom.parseString(xmlStr)
...

These vulnerabilities are gone from scan report. But AppScan still notify me about vulnerabilities where from standard xml package are importing any functions/classes. For example classes from ElementTree to modify/build xml tree:

from xml.etree.cElementTree import (  # vulnerability here
SubElement, Element, ElementTree)
import defusedxml.cElementTree as et
...
template = et.parse(template_filename)  # safe parsing

root = template.getroot()
email_list_el = root.find('emails').find('list')

for email_address in to_list:
    SubElement(email_list_el , 'string').text = email_address 
    root.find('subject')[0].text = subject
    root.find('body')[0].text = body
...

Can this be considered a vulnerability if xml.dom.minidom is used only for writing XML?

Answer 1

ElementTree is not secured against maliciously constructed data. See list of vulnerabilities . Consider using defusedxml instead.