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CyberPower Systems PowerPanel 3.1.2 XXE Out-Of-Band Data Retrieval

High

Advisory ID

ZSL-2016-5338

Release Date

08 July 2016

Vendor

CyberPower Systems, Inc. - https://www.cyberpowersystems.com

Affected Version

3.1.2 (37567) Business Edition

CVE

N/A

Tested On

Microsoft Windows 7 Ultimate SP1 EN, Microsoft Windows 8, Microsoft Windows Server 2012, Linux (64bit), MacOS X 10.6, Jetty(7.5.0.v20110901), Java/1.8.0_91-b14, SimpleHTTP/0.6 Python/2.7.1

Summary

The PowerPanel® Business Edition software from CyberPower provides IT professionals with the tools they need to easily monitor and manage their backup power. Available for compatible CyberPower UPS models, this software supports up to 250 clients, allowing users remote access (from any network PC with a web browser) to instantly access vital UPS battery conditions, load levels, and runtime information. Functionality includes application/OS shutdown, event logging, hibernation mode, internal reports and analysis, remote management, and more.

Description

PowerPanel suffers from an unauthenticated XML External Entity (XXE) vulnerability using the DTD parameter entities technique resulting in disclosure and retrieval of arbitrary data on the affected node via out-of-band (OOB) attack. The vulnerability is triggered when input passed to the xmlservice servlet using the ppbe.xml script is not sanitized while parsing the xml inquiry payload returned by the JAXB element translation.

	C:\Program Files (x86)\CyberPower PowerPanel Business Edition\web\work\ROOT\webapp\WEB-INF\classes\com\cyberpowersystems\ppbe\webui\xmlservice\
	------------------------
XmlServiceServlet.class:
------------------------

 private InquirePayload splitInquirePayload(InputStream paramInputStream)
   throws RequestException
 {
   try
   {
     JAXBContext localJAXBContext = JAXBContext.newInstance("com.cyberpowersystems.ppbe.core.xml.inquiry");
    Unmarshaller localUnmarshaller = localJAXBContext.createUnmarshaller();
    JAXBElement localJAXBElement = (JAXBElement)localUnmarshaller.unmarshal(paramInputStream);
    return (InquirePayload)localJAXBElement.getValue();
  }
  catch (JAXBException localJAXBException)
  {
    localJAXBException.printStackTrace();
    throw new RequestException(Error.INQUIRE_PAYLOAD_CREATE_FAIL, "Translate input to JAXB object failed.");
  }
}

Proof of Concept

powerpanel_xxe.txtTXT

Disclosure Timeline

22.06.2016Vulnerability discovered.

23.06.2016Contact with the vendor.

04.06.2016No response from the vendor.

05.07.2016Contact with the vendor.

07.07.2016No response from the vendor.

08.07.2016Public security advisory released.

Credits

Vulnerability discovered by Gjoko Krstic

References