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  <title>XML parsing vulnerable to XXE - Roslyn Security Guard</title>
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        <h2>XML parsing vulnerable to XXE</h2>
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<p>
    The XML parser is configured incorrectly. The operation could be vulnerable to XML eXternal Entity (XXE) processing.
</p>

<h3>Risk</h3>

<p>

</p>

<h3>Vulnerable Code</h3>

<pre>
XmlReaderSettings settings = new XmlReaderSettings();
settings.ProhibitDtd = false;
XmlReader reader = XmlReader.Create(inputXml, settings);
</pre>

<pre>
XmlReaderSettings settings = new XmlReaderSettings();
settings.DtdProcessing = DtdProcessing.Parse;
XmlReader reader = XmlReader.Create(inputXml, settings);
</pre>

<h3>Solution</h3>

<pre>
//Avoid overriding the secure settings
XmlReader reader = XmlReader.Create(inputXml);
</pre>

<pre>
XmlReaderSettings settings = new XmlReaderSettings();
settings.ProhibitDtd = true;
XmlReader reader = XmlReader.Create(inputXml, settings);
</pre>

<pre>
XmlReaderSettings settings = new XmlReaderSettings();
settings.DtdProcessing = DtdProcessing.Ignore;
XmlReader reader = XmlReader.Create(inputXml, settings);
</pre>

<h3>References</h3>

<p>
    <a href="http://cwe.mitre.org/data/definitions/611.html">CWE-611: Improper Restriction of XML External Entity Reference ('XXE')</a><br />
    <a href="https://www.securecoding.cert.org/confluence/pages/viewpage.action?pageId=61702260">CERT: IDS10-J. Prevent XML external entity attacks</a><br />
    <a href="https://www.owasp.org/index.php/XML_External_Entity_%28XXE%29_Processing">OWASP.org: XML External Entity (XXE) Processing</a><br />
    <a href="http://www.ws-attacks.org/index.php/XML_Entity_Expansion">WS-Attacks.org: XML Entity Expansion</a><br />
    <a href="http://www.ws-attacks.org/index.php/XML_External_Entity_DOS">WS-Attacks.org: XML External Entity DOS</a><br />
    <a href="http://www.ws-attacks.org/index.php/XML_Entity_Reference_Attack">WS-Attacks.org: XML Entity Reference Attack</a><br />
    <a href="http://blog.h3xstream.com/2014/06/identifying-xml-external-entity.html">Identifying Xml eXternal Entity vulnerability (XXE)</a>
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