From 32b20685dd02910e7313d72dbe2ee001fdcdc904 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Thu, 19 Mar 2026 16:06:54 +0000
Subject: [PATCH] =?UTF-8?q?=F0=9F=94=92=20Fix=20XXE=20vulnerability=20in?=
 =?UTF-8?q?=20xml-validator?=
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🎯 What: Replaced lxml.etree.parse with defusedxml.lxml.parse in xml-validator.py to prevent XML External Entity (XXE) vulnerabilities. Added defusedxml and lxml to requirements.txt.
⚠️ Risk: If left unfixed, the application could be vulnerable to XXE attacks when parsing malicious XML or XSD files, potentially leading to unauthorized data disclosure or denial of service.
🛡️ Solution: defusedxml acts as a drop-in replacement that strictly disables external entity resolution by default, successfully mitigating the XXE attack vector while maintaining compatibility with lxml.etree.XMLSchema and validation.

Co-authored-by: rdale-dev <203160809+rdale-dev@users.noreply.github.com>
---
 requirements.txt     | 2 ++
 src/xml-validator.py | 5 +++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/requirements.txt b/requirements.txt
index fb6c7ed..f344230 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1,3 @@
 pandas
+defusedxml
+lxml
diff --git a/src/xml-validator.py b/src/xml-validator.py
index 058669d..e0281ba 100644
--- a/src/xml-validator.py
+++ b/src/xml-validator.py
@@ -7,6 +7,7 @@
 import sys
 import xml.etree.ElementTree as ET
 from lxml import etree
+from defusedxml.lxml import parse as defused_parse
 import logging # Keep standard logging import for levels like logging.INFO
 import re
 
@@ -28,11 +29,11 @@ def validate_against_xsd(xml_file, xsd_file):
     """
     try:
         # Parse the XSD schema
-        xmlschema_doc = etree.parse(xsd_file)
+        xmlschema_doc = defused_parse(xsd_file)
         xmlschema = etree.XMLSchema(xmlschema_doc)
         
         # Parse the XML file
-        xml_doc = etree.parse(xml_file)
+        xml_doc = defused_parse(xml_file)
         
         # Validate
         is_valid = xmlschema.validate(xml_doc)