SEC Consult Security Advisory < 20090305-0 > ======================================================================== title: NextApp Echo XML Injection Vulnerability program: NextApp Echo vulnerable version: Echo2 < 2.1.1 homepage: http://echo.nextapp.com/site/echo2 found: Feb. 2008 by: Anonymous / SEC Consult Vulnerability Lab permanent link: http://www.sec-consult.com/files/20090305-0_echo_nextapp_xml_injection.txt ======================================================================== Vendor description: ------------------- Echo is a platform for building web-based applications that approach the capabilities of rich clients. The applications are developed using a component-oriented and event-driven API, eliminating the need to deal with the "page-based" nature of browsers. To the developer, Echo works just like a user interface toolkit. Vulnerability overview: ----------------------- Unverified XML Data is passed from the client (Webbrowser) to the NextApp Echo Engine and consequently to an underlying XML Parser. This leading to a typical XML Injection scenario. Vulnerability description: -------------------------- All XML requests for the framework are created by javascript and than sent to the Server via POST HTTP requests. A typical requests would look like the following: ---cut here--- <client-message xmlns="http://www.nextapp.com/products/echo2/climsg" trans-id="3" focus="c_25"><message-part xmlns="" processor="EchoPropertyUpdate"><property component-id="c_25" name="text">aa</property><property component-id="c_25" name="horizontalScroll" value="0"/><property component-id="c_25" name="verticalScroll" value="0"/></message-part><message-part xmlns="" processor="EchoAction"><action component-id="c_25" name="action"/></message-part></client-message> ---cut here--- By manipulating the POST content it is possible to inject arbitrary XML declarations- and tags. Proof of concept: ----------------- The following entity declaration would create a new XML entity with the content of the boot.ini file which can be referenced in the following XML request content: ---cut here--- <?xml version="1.0"?><!DOCTYPE sec [<!ELEMENT sec ANY><!ENTITY mytestentity SYSTEM "file:///c:\boot.ini">]> ---cut here--- Vulnerable versions: -------------------- NextApp Echo v2.1.0.rc2 Vendor contact timeline: ------------------------ 2009/02/16: Vendor notified via email 2009/02/24: Patch available Patch/Workaround: ----------------- The vendor has released an update which addresses the vulnerability. The update can be downloaded at: http://echo.nextapp.com/site/node/5742 -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SEC Consult Unternehmensberatung GmbH Office Vienna Mooslackengasse 17 A-1190 Vienna Austria Tel.: +43 / 1 / 890 30 43 - 0 Fax.: +43 / 1 / 890 30 43 - 25 Mail: research at sec-consult dot com www.sec-consult.com # EOF SEC Consult Vulnerability Lab / @2009 # milw0rm.com [2009-03-10]