SugarCRM <= 6.5.18 (SAML Authentication) XML External Entity Vulnerability

• Software Link:

• Affected Versions:

Version 6.5.18 CE and prior versions.

• Vulnerability Description:

The vulnerable code is located in the constructor method of the SamlResponse class:

    function __construct($settings, $assertion) {
      $this->settings = $settings;
      $this->assertion = base64_decode($assertion);
      $this->xml = new DOMDocument();

Which is being called by the authenticateUser method of the SAMLAuthenticateUser class:

        $samlresponse = new SamlResponse($settings, $_POST['SAMLResponse']);

User input passed through the “SAMLResponse” POST parameter isn’t properly sanitized before being used in a call
to the “DOMDocument::loadXML()” method, and there are no calls to the “libxml_disable_entity_loader()” function.
This can be exploited by unauthenticated attackers to carry out XML External Entity (XXE) attacks. Successful
exploitation of this vulnerability requires SAML authentication to be enabled (disabled by default).

• Solution:

Update to version 6.5.19 CE or higher.

• Disclosure Timeline:

[15/10/2014] – Vendor notified
[18/10/2014] – Vendor acknowledgement
[15/12/2014] – Version 6.5.19 CE released:
[29/04/2015] – CVE number requested
[23/06/2016] – Public disclosure

• CVE Reference:

The Common Vulnerabilities and Exposures project (
has not assigned a CVE identifier for this vulnerability.

• Credits:

Vulnerability discovered by Egidio Romano.